A case of mediastinal angiomyolipoma

Angiomyolipoma is a common tumor of the kidney but has rarely been found in the mediastinum. We report a case of angiomyolipoma of the posterior mediastinum in a 62-year-old woman. She experienced exertional dyspnea and intermittent cough at admission. Computed tomography indicated a tumor located at the left paravertebral and upper posterior mediastinum and MRI imaging demonstrated a mass with low signal intensity in T1-weighted image at T4-5 level. Thoracotomy was done for surgical removal of the tumor and histologic examination revealed a mesenchymal tumor composed of mature fat, capillaries and smooth muscle fibers. The tumor was immunohistochemically positive for CD34 and factor-VIII (for vascular component) smooth muscle actin (for smooth muscle component) and S-100 protein (for fat component). There have been four case reports about mediastinal angiomyolipoma, namely three Japanese cases and one French case. It is suggested that angiomyolipoma could be considered for the differential diagnosis of mediastinal tumors.

In vitro antimicrobial activity of a chitooligosaccharide mixture against Actinobacillus actinomycetemcomitans and Streptococcus mutans

The purpose of this study was to evaluate the in vitro antibacterial activity of a chitooligosaccharide mixture (MW 2000-30000 Da) with a deacetylation degree of 91.5% against two representative oral pathogens, Actinobacillus actinomycetemcomitans and Streptococcus mutans. A 0.1% concentration of the chitooligosaccharides (derived from the exoskeletons of marine crustaceans) was used to estimate antibacterial activity. Approximately 2 logcolony forming units (CFU)/ml of A. actinomycetemcomitans were inactivated by 0.1% chitosan after 30 min, while 120 min exposure inactivated about 4.5 logCFU/ml of this organism. In contrast, the level of inactivation against S. mutans was less than 0.5 logCFU/ml after an exposure of up to 120 min. Electron microscopy showed that the exposure of A. actinomycetemcomitans to the chitooligosaccharides resulted in the disruption of cell membranes and that it could be considered for the treatment of periodontal diseases associated with A. actinomycetemcomitans.

Characterization and large-scale expression of the recombinant cysteine proteinase from adult Clonorchis sinensis

Cysteine proteinases play important roles in the pathogenesis of several parasitic infections and have been proposed as targets for the structure-based approach of drug design. As the first step toward applying this strategy to design inhibitors as antiparasitic agents for Clonorchis sinensis, we overexpressed and characterized the 24-kDa cysteine proteinase from adult worms. First, the partial cysteine proteinase gene from C. sinensis was cloned by performing reverse transcription polymerase chain reaction (RT-PCR) with degenerate oligonucleotide primers derived from conserved cysteine proteinase sequences. The 5' and the 3' regions of the cysteine proteinase gene were amplified using the PCR protocol for the rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The cDNA has an open reading frame of 981 bp, and the deduced amino acid sequence shares similarity with the cathepsin L-like cysteine proteinases from Schistosoma mansoni, Paragonimus westermani metacercaria, Fasciola hepatica, and human cathepsin L by 52%, 47%, 34%, and 29%, respectively. The cysteine proteinase was then overexpressed in the yeast Pichia pastoris as an active enzyme on a large-scale basis (19.7 mg/L). The active recombinant enzyme was purified from culture media using a Ni2+-NTA-agarose affinity column and gel filtration chromatography. This 24-kDa recombinant protein exhibited a substrate preference for Z-Phe-Arg-AMC (benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amino-4-methyl-coumarin) compared with Z-Arg-Arg-AMC, and the activity was inhibited by E-64 (L-trans-epoxysuccinylleucylamido(4-quanidino)butane).

Recording of optical near fields in remote locations by near-field holography

We propose a method of near-field recording in a space that is quite apart from the original source (generator) of optical near fields. The method is based on the recently developed technique of near-field holography. Experiments based on our method have shown that near fields that originate from sub-diffraction-limit-sized objects can be stored in a photorefractive crystal 2 mm apart from the crystal surface, resulting in the retrieval of sub-diffraction-limit-sized spots. This means that our scheme can provide a method for multilayer (stackwise) near-field storage and, thus, contribute to a significant enhancement of the storage capacity of near-field optical memory.

N-acetylcysteine induces cell cycle arrest in hepatic stellate cells through its reducing activity

Activation of hepatic stellate cells (HSC) has been identified as a critical step in hepatic fibrogenesis and is regulated by several factors including cytokines and oxidative stress. However, the molecular mechanism for HSC inactivation is not well understood. We investigated an N-acetyl-L-cysteine (NAC)-mediated signaling pathway involved in HSC inactivation. NAC, which acting through its reducing activity, induced cell arrest at G1 via the mitogen-activated protein kinase (MAPK) kinase (MEK)/MAPK pathway in a Ras-independent manner. The sustained activation of this extracellular signal-regulated kinase induced the expression of p21(Cip1/WAF1), a cell cycle-dependent kinase inhibitor, and mediated cell growth arrest through the Sp1 transcription activator-dependent mechanism. These effects of NAC were all reversed by treatment of HSC with MEK inhibitor PD98059 followed by culturing HSC on type I collagen-coated flasks. The collagen-mediated suppression of NAC-induced arrest may be due to an overriding of the cell cycle arrest through an acceleration of integrin-induced cell growth. NAC action is actually dependent on modulating the redox states of cysteine residues of target proteins such as Raf-1, MEK, and ERK. In conclusion, an understanding of the NAC signaling pathway in HSC should provide the theoretical basis for clinical approaches using antioxidant therapies in liver fibrosis.

Predicting the rotationally neutral state of the femur by comparing the shape of the contralateral lesser trochanter

The rotationally neutral state of the femur was measured by comparing the shape of the contralateral lesser trochanter in 100 adults. Three observers predicted a position presumed to be neutral by comparing the shape of the neutrally positioned contralateral lesser trochanter previously recorded by C-arm image intensification. The mean (SD) angular discrepancy between the neutral point and the predicted angle was 3.4 degrees (+/- 2.4) without interobserver variation (P = .87). Seventy-seven percent indicated the value within 4 degrees, and none of the observations exceeded 15 degrees. These findings suggest the outline of the contralateral lesser trochanter may be a useful reference during surgical treatment of femoral fractures to minimize rotational deformity.

Induction of angiogenesis by expression of soluble type II transforming growth factor-beta receptor in mouse hepatoma

The biological effect of transforming growth factor-beta (TGF-beta) is cell type-specific and complex. The precise role of TGF-beta is not clear in vivo. To elucidate the regulation mechanism of endogenous TGF-beta on hepatoma progression, we modified the MH129F mouse hepatoma cell with a retroviral vector encoding the extracellular region of type II TGF-beta receptor (TRII). Soluble TRII (TRIIs) blocked TGF-beta binding to TRII on the membrane of hepatoma cells. Growth of MH129F cells was inhibited by TGF-beta1 treatment; however, soluble TRII-overexpressing cells (MH129F/TRIIs) did not show any change in proliferation after TGF-beta1 treatment. MH129F/TRIIs cells also increased vascular endothelial growth factor (VEGF) expression, endothelial cell migration, and tube formation. Implantation of MH129F/TRIIs cells into C3H/He mice showed the significantly enhanced tumor formation. According to Western blot and protein kinase C assay, the expression of VEGF, KDR/flk-1 receptor, and endothelial nitric-oxide synthase was enhanced, and the phosphorylation activity of protein kinase C was increased up to 3.7-fold in MH129F/TRIIs tumors. Finally, a PECAM-1-stained intratumoral vessel was shown to be 4.2-fold higher in the MH129F/TRIIs tumor. These results indicate that VEGF expression is up-regulated by a blockade of endogenous TGF-beta signaling in TGF-beta-sensitive hepatoma cells and then stimulates angiogenesis and tumorigenicity. Therefore, we suggest that endogenous TGF-beta is a major regulator of the VEGF/flk-1-mediated angiogenesis pathway in hepatoma progression.

Effects of Polyamines on TNFalpha- or Tamoxifen-induced Apoptosis in Human Breast Cancer Cells

PURPOSE

To investigate the effects of polyamines on tumor necrosis factor alpha (TNFalpha)-or tamoxifen (TAM)-induced apoptosis in estrogen receptor (ER)-positive MCF- 7 and ER-negative MDA-MB-231 human breast cancer cells.

MATERIALS AND METHODS

Cell viability was assessed by using MTT assay. Reactive oxygen species (ROS) generation was measured using 2', 7'-dichlorofluorescin diacetste (DCFDA) by fluorescence plate reader. DNA fragmentation was assessed by 1.5% agarose gel electrophoresis.

RESULTS

TNFalpah and TAM showed significant dose- and time- dependent inhibitory effects on the growth of MCF-7 human cells. However, the growth of MDA-MB-231 cells were not inhibited by TNFalpha or TAM treatment. The generation of ROS was increased in dose-and time-dependent manner by TNFalpha treatment in MCF-7 cells. Polyamines, especially spermine suppressed TNFalpha-induced ROS generation in MCF-7 cells. Antioxidant effects of polyamines were also demonstrated by DNA fragmentation, cell morphology as well as ROS generation assay. Polyamines also blocked TAM-induced cell death in MCF-7 cell. However, MDA-MB-231 cells showed resistance to the cytotoxic effects of TNFalpha or TAM.

CONCLUSION

These results suggest that polyamines may prevent TNFalpha or TAM-induced apoptosis in MCF-7 human breast cancer cells.

Estrogen attenuates cell death induced by carboxy-terminal fragment of amyloid precursor protein in PC12 through a receptor-dependent pathway

In the present study, we investigated effects of estrogen on cell death induced by carboxy-terminal fragment of amyloid precursor protein (CT), a candidate causative substance in the pathogenesis of Alzheimer's disease. 17 beta-Estradiol attenuated CT-induced cell death in PC12 cells, whereas 17 alpha-estradiol, nonestrogenic stereoisomer, did not exert any significant protective effect on CT-induced cell death. These results suggest that protective effects of estrogen may be mediated by estrogen receptor (ER) in PC12 cells. To confirm the results, we determined the effects of tamoxifen, an estrogen receptor antagonist. Tamoxifen blocked the protective effects of 17 beta-estradiol, although it did not affect those of 17 alpha-estradiol. Overall, it might be thought that the protective effect of estradiol on CT-induced cell death is achieved by hormonal properties mediated through the estrogen receptor rather than the structural properties as a reducing agent.

Up-regulated eNOS protects blood-retinal barrier in the L-arginine treated ischemic rat retina

Using immunoblot analysis and immunocytochemistry, we investigated expression and cellular localization of endothelial nitric oxide synthase (eNOS) and proliferating cell nuclear antigen (PCNA) in the l-arginine treated ischemic rat retina. In parallel, we tested whether the blood-retinal barrier was intact by immunocytochemistry using an antiserum against IgG. In the l-arginine-treated ischemic retina, the magnitude of the increased eNOS was higher, and PCNA was expressed in endothelial cells as well as in neurons in the inner retina during the whole experimental period. Finally, IgG leakage was not detectable in the l-arginine-treated ischemic retina. Our results clearly suggest that the increased NO production by eNOS may be essential for the survival of endothelial cells in the rat retina following transient ischemia.

Antibacterial activity in extracts of Camellia japonica L. petals and its application to a model food system

The potential presence of naturally occurring antimicrobials in petals of Camellia japonica L., a member of the tea family, was investigated against foodborne pathogens in microbiological media and food. Petals of the camellia flower (C. japonica L.) were extracted with methanol and fractionated into basic, acidic, and neutral fractions. The acidic fraction (equivalent to 1.0 g of raw sample per disk) produced an inhibitory zone of 14 to 19 mm (diameter) in a disk assay against the pathogens Salmonella Typhimurium DT104, Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus on agar plates. Silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, and preparative purification by high-pressure liquid chromatography were used to purify compounds in the fraction. The mass spectrum of the antibacterial compound isolated had a molecular ion (M+) of m/z 116 and showed good conformity with the spectrum of fumaric acid (HOOC-CH=CH-COOH). An aqueous extract from the petals of C. japonica L. had an inhibitory effect on growth of all pathogens at 37 degrees C in microbiological media by increasing the lag phase. None of the microorganisms was inhibited completely. Milk was used as a model food system. Aqueous extract at a concentration of 100 mg/ml was bacteriostatic against all the foodborne pathogens in the milk stored at 25 degrees C for up to 4 days.

C-terminal fragment of amyloid precursor protein induces astrocytosis

One of the pathophysiological features of Alzheimer's disease is astrocytosis around senile plaques. Reactive astrocytes may produce proinflammatory mediators, nitric oxide, and subsequent reactive oxygen intermediates such as peroxynitrites. In the present study, we investigated the possible role of the C-terminal fragment of amyloid precursor protein (CT-APP), which is another constituent of amyloid senile plaque and an abnormal product of APP metabolism, as an inducer of astrocytosis. We report that 100 nM recombinant C-terminal 105 amino acid fragment (CT105) of APP induced astrocytosis morphologically and immunologically. CT105 exposure resulted in activation of mitogen-activated protein kinase (MAPK) pathways as well as transcription factor NF-kappaB. Pretreatment with PD098059 and/or SB203580 decreased nitric oxide (NO) production and nuclear factor-kappa B (NF-kappaB) activation. But inhibitors of NF-kappaB activation did not affect MAPKs activation whereas they abolished NO production and attenuated astrocytosis. Furthermore, conditioned media derived from CT105-treated astrocytes enhanced neurotoxicity and pretreatment with NO and peroxynitrite scavengers attenuated its toxicity. These suggest that CT-APP may participate in Alzheimer's pathogenesis through MAPKs- and NF-kappaB-dependent astrocytosis and iNOS induction.

Effect of bradykinin on cultured bovine corneal endothelial cells

PURPOSE

To clarify the effect of bradykinin on cytosolic free calcium mobilization and cell proliferation in cultured bovine corneal endothelial cells (BCEC).

METHODS

The cytosolic free calcium concentration (Ca2+]i) was measured with the InCa(TM) Imaging System after the treatment of bradykinin (10(-11) to 10(-7) M) alone or with the pretreatments of EGTA, bradykinin receptor (Bk1 and Bk2) antagonists and an inhibition of phospholipase C (U-73122). Also, the effect of bradykinin on cell proliferation in BCEC was evaluated using cell counts.

RESULTS

In BCEC, [Ca2+]i in the resting state was 87 +/- 9 nM. Bradykinin induced an increment of [Ca2+]i in a concentration-dependent manner and its 50% effective concentration was approximately 5 x 10(-11) M. A [Ca2+]i increment at 10(-8) M bradykinin was inhibited with the pretreatment of EGTA, an extracellular calcium chelator. U-73122 (5 x 10(-6) M) attenuated the bradykinin-induced [Ca2+]i increment. The pretreatment of HOE-140 (Bk2 antagonist) almost attenuated the bradykinin (10(-8) M)-induced [Ca2+]i increase, but des-Arg9-[Leu(8)]-bradykinin (Bk1 antagonist) did not suppress it. To investigate the physiological effect of bradykinin, the effect of bradykinin on cell proliferation was studied. 10(-8) M of bradykinin produced a significant increase in cell numbers. This mitogenic effect of bradykinin was inhibited by the Bk2 antagonist.

CONCLUSIONS

Bradykinin-induced stimulation of the signal transduction pathway in BCEC is coupled with the Bk2 type receptor. Furthermore, bradykinin produces the mitogenic effect in BCEC.

Production and characterization of monoclonal antibodies against amphiphysins

Amphiphysin I and II, proteins enriched in nerve terminals, form heterodimers and interact with dynamin and synaptojanin through their Src homology 3 (SH3) domain. In order to study the expression profile of Amphs in cells and tissues and the interaction state with other cellular molecules, we have prepared specific monoclonal antibodies (mAbs) designed to bait N-terminus, middle part, and C-terminus domains of Amph I, respectively by immunizing with the expressed smaller domain molecules using the GST gene fusion system. The expression of Amphs was found to be most abundant in PC12 cells, followed by B103 cells and vascular smooth muscle cells. Western blot analysis showed a relatively high level expression of Amphs that were found in both mouse and rat brain. There appeared to be some species difference in the expression pattern, i.e. Amphs are present more in the testis than in the lungs in rats, however, they are reversed in mice. Characterization of the mAbs revealed that clone 14-23 precipitated Amph I and II, whereas clone 8-2 could only precipitate Amph I. In addition, clathrin and dynamin in a complex with Amph were captured in the precipitate formed by mAbs and identified by the Western blot analysis. Cellular distribution of Amph was visualized with confocal immunofluorescence microscopy performed using the labeled-mAbs. Taken together, these results demonstrated that mAbs provided an excellent measure for studying Amphs' expression profile and their interacting proteins.

The protective role of HSP90 against 3-hydroxykynurenine-induced neuronal apoptosis

3-hydroxykynurenine (3HK), an endogenous metabolite of tryptophan in the kynurenine pathway, is a potential neurotoxin in several neurodegenerative disorders. Stabilizing protein structure, heat shock proteins (HSPs) have diverse roles as molecular chaperones to mediate stress tolerance. In the present study, we investigated the possible protective role of HSPs against 3HK induced neuronal cell death. Here we report that 3HK induced in a dose- and time-dependent manner neuronal cell death in neuroblastoma SK-N-SH cells. The cell death showed characteristic apoptotic features such as cell shrinkage, plasma membrane blebbing, chromatin condensation, and nuclear condensation and fragmentation. Furthermore, SK-N-SN cells were protected from 3HK induced cytotoxicity by prior elevation of HSPs expression. Our results show that the protective effect was abolished by HSP90 anti-sense oligonucleotides while not by HSP27 and HSP70 anti-sense oligonucleotides. Also, our result shows that HSP90 effectively inhibits caspases activities leading to the apoptosis. These results suggest that 3HK induces apoptosis in neuroblastoma SK-N-SN cells and that HSP90 is major contributing protein component of protection against 3HK induced apoptosis.

Enhancement of natural killer cell-mediated cytotoxicity by coexpression of GM-CSF/B70 in hepatoma

On investigating the role of granulocyte-macrophage colony-stimulating factor (GM-CSF) and costimulatory molecule, B70, in antitumor immunity, we have found important effects of GM-CSF/B70 coexpression in the interaction with natural killer (NK) cells. We used the pLSN vector system to contain the neomycin-resistant gene and LTR promoter. The pLSNGM-CSF, pLSNB70 and pLSNB70/GM-CSF, pLSN vectors each containing GM-CSF, B70, and B70/GM-CSF cDNA, respectively, were constructed. They were transfected into human hepatocellular carcinoma cell (SK-HEP1), and stable cells (SK-pLSN, SK-GM, SK-B70 and SK-BG) were selected after neomycin treatment. According to enzyme-linked immunosorbent analysis and FACS, we showed that expression of GM-CSF was increased up to 23-fold in SK-GM and SK-BG cells, and also expression of B70 was induced at least 76-97% in SK-B70 and SK-BG cells. Expression of B70 was remarkably increased by autocrine effect of GM-CSF in SK-BG cells. Primary cytolytic ability of GM-CSF and B70 significantly increased almost 4-fold (effector/target ratio, 100:1) in SK-BG cells. In in vivo studies, SK-BG cells showed much less subcutaneous tumor formation in nude mice accompanying increased NK cell proliferation and cytotoxicity. Therefore, these results suggest that combining expression of GM-CSF and B70 may enhance NK-mediated cytotoxicity, and then induce the antitumor immunity in hepatoma transplanted into nude mice.

Births of freemartins derived from embryos reconstructed with ear fibroblasts

Although the combination of artificial insemination (AI) and embryo transfer (ET) is effective for preventing large offspring syndrome in clone cattle production, it may cause freemartinism. In this study, 51 reconstructed embryos were transferred to artificially inseminated recipients. Of those 9 twin pregnancies, three delivered male and female offsprings. The females had tufts of long coarse hair and short blind pouch at the vaginal end. At necropsy, hypoplastic testicles and epididymis, which connected to the uterus through the spermatic cord, were found and seminal vesicles were also noted. All females had mixed sex chromosome configuration (60, XX and 60, XY). These results suggest that the combined ET program can cause freemartinism, which reduces the efficiency of clone cattle production.

HWY-289, a novel semi-synthetic protoberberine derivative with multiple target sites in Candida albicans

The antifungal properties of 515 synthetic and semi-synthetic protoberberines were investigated. HWY-289 was chosen for further study because it exhibited the most significant anti-Candida activity (MICs were 1.56 mg/L for Candida albicans and Candida krusei; 6.25 mg/L for Candida guilliermondii) but did not demonstrate toxicity in rats. HWY-289 inhibited the incorporation of L-[methyl-(14)C]methionine into the C-24 of ergosterol in whole cells of C. albicans (IC(50) 20 microM). However, HWY-289 (100 microM) had no effect on mammalian cholesterol biosynthesis in rat microsomes while miconazole (100 microM) was a potent inhibitor of cholesterol biosynthesis under identical assay conditions. A second major target site for HWY-289 was identified that involves cell wall biosynthesis in C. albicans. HWY-289 was a potent inhibitor of the chitin synthase isozymes CaCHS1 and CaCHS2, with IC(50) values of 22 microM for each enzyme. The effect was highly specific in that HWY-289 had no significant effect on C. albicans CaCHS3 (IC(50) > 200 microM). Thus, HWY-289 compared favourably with well-established antifungal agents as an inhibitor of the growth of Candida species in vitro, and may have considerable potential as a new class of antifungal agent that lacks toxic side effects in the human host.

Selective serotonin reuptake inhibitors for aggressive behavior in patients with dementia after head injury

Head injury of any severity can result in acute and chronic neuropsychiatric symptoms. After head injury, aggressive behaviors can be disabling to victims and stressful to their families. When aggression is compounded by dementia, treatment can be more difficult. Psychotropic agents can attenuate aggressive behaviors associated with mental disorders. Three patients with dementia and chronic aggression after head injury responded favorably to selective serotonin reuptake inhibitors.

Inhibition of neuronal apoptosis by polyunsaturated fatty acids

The effect of polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (22:6n-3; DHA) and arachidonic acid (20:4n-6; AA), on apoptotic cell death was evaluated based on DNA fragmentation and caspase-3 activity induced by serum starvation using Neuro-2A and PC-12 cells. The presence of 20:4n-6 in the medium during serum starvation decreased DNA fragmentation and this initial protective effect was diminished with prolonged serum starvation. The observed protective effect of 20:4n-6 was not affected by the inhibitors of cyclooxygenase (COX) and lipoxygenase. Conversely, 22:6n-3 became protective only after the enrichment of cells with this fatty acid at least for 24 h prior to the serum deprivation. DNA fragmentation as well as caspase-3 activity was reduced in 22:6n-3 enriched cells with a concomitant decrease in protein and mRNA levels. During the enrichment period, 22:6n-3 steadily increased its incorporation into PS leading to a significant increase in the total PS content; the protective effect of 22:6n-3 paralleled the PS accumulation. Neither direct exposure of cells to nor enrichment with 18:1n-9 had any protective effect. In conclusion, it is proposed that 20:4n-6 prevents neuronal apoptosis primarily due to the action of nonesterified 20:4n-6 but 22:6n-3, at least in part, through PS accumulation.

Citalopram for verbal agitation in patients with dementia

Various behaviors can be associated with dementing disorders. Management of these behaviors is often challenging to caregivers and clinicians. Verbal agitation such as talking constantly, screaming, and repeating phrases and noises is one of the most frequently encountered behaviors in the long-term care setting. We report two cases in which verbal agitation favorably responded to citalopram, a selective serotonin reuptake inhibitor. We also discuss some other factors possibly associated with this response. Nonetheless, citalopram appears to be an added option in the treatment of verbal agitation in demented patients.

The ep -->e'p eta reaction at and above the S11(1535) baryon resonance

New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.

The growth inhibition of hepatoma by gene transfer of antisense vascular endothelial growth factor

BACKGROUND

Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis and tumor growth in solid tumors. Therefore, to induce tumor regression, antiangiogenic agents to block VEGF need to be administered repeatedly.

METHOD

We constructed the recombinant mammalian expression vector bearing an antisense-VEGF cDNA, pZeoVEGFa. We examined the effect of pZeoVEGFa on the growth of SK-HEP1 hepatoma cells, bovine capillary endothelial (BCE) cells, and tubule formation of BCE cells in fibrin gel. To evaluate the function of pZeoVEGFa in vivo, we implanted SK-HEP1 hepatoma cells subcutaneously into nude mice.

RESULTS

In SK-HEP1 hepatoma cells, we showed that the synthesis of VEGF protein was suppressed by the stable and transient transfection of pZeoVEGFa. pZeoVEGFa inhibited the proliferation of BCE cells and significantly suppressed tubule formation of BCE cells. pZeoVEGFa inhibited a morphological change from a round shape to an elongated spindle shape in fibrin gel. When pZeoVEGFa was injected peritumorally by liposomes, tumor growth was inhibited.

CONCLUSION

Endothelial cell proliferation, tubule formation and tumor growth may be diminished by down-regulation of endogenous VEGF expression in tumor cells or tissue. These findings indicate that the efficient down-regulation of the VEGF produced by tumor cells using antisense strategies has an antitumor effect. We suggest that VEGF-targeted antiangiogenic gene therapy could be an effective strategy to treat VEGF-producing tumors.