[show abstract][hide abstract] ABSTRACT: Neuroblastoma (NB), originating from neural crest cells, is the most common extracranial tumor of childhood. Retinoic acid (RA) which is the biological active form of vitamin A regulates differentiation of NB cells, and RA derivatives have been used for NB treatment. PPARα (peroxisome proliferator-activated receptor) plays an important role in the oxidation of fatty acids, carcinogenesis, and differentiation. URG4/URGCP gene is a proto-oncogene and that overexpression of URG4/URGCP is associated with metastasis and tumor recurrence in osteosarcoma. It has been known that URG4/URGCP gene is an overexpressed gene in hepatocellular carcinoma and gastric cancers. This study aims to detect gene expression patterns of PPARα and URG4/URGCP genes in SH-SY5Y NB cell line after RA treatment. Expressions levels of PPARα and URG4/URGCP genes were analyzed after RA treatment for reducing differentiation in SH-SY5Y NB cell line. To induce differentiation, the cells were treated with 10 μM RA in the dark for 3-10 days. Gene expression of URG4/URGCP and PPARα genes were presented as the yield of polymerase chain reaction (PCR) products from target genes compared with the yield of PCR products from the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. SH-SY5Y cells possess small processes in an undifferentiated state, and after treatment with RA, the cells developed long neurites, resembling a neuronal phenotype. PPARα gene expression increased in RA-treated groups; URG4/URGCP gene expression decreased in SH-SY5Y cells after RA treatment compared with that in the control cells. NB cell differentiation might associate with PPARα and URG4/URGCP gene expression profile after RA treatment.
[show abstract][hide abstract] ABSTRACT: Retinoic acid (RA) plays important roles in development, growth, and differentiation by regulating the expression of its target genes. The pro-apoptotic Bax gene may form channels through oligomerization in the mitochondrial membrane and facilitate the cytosolic release of cytochrome c. The anti-apoptotic Bcl-2 gene can inhibit this process. Up-regulated gene 4/Upregulator of cell proliferation (URG4/URGCP) is a novel gene located on 7p13. URG4/URGCP also stimulates cyclin D1 (CCND1) mRNA expression, and RNAi-mediated URG4/URGCP silencing diminishes CCND1 mRNA expression in HepG2 cells. In this study, the effects of RA treatment on URG4/URGCP, CCND1, Bcl-2 and Bax gene expression changes in undifferentiated and differentiated SHSY5Y neuroblastoma cells was analyzed. SHSY5Y cells were cultured in the appropriate conditions. To induce differentiation, the cells were treated with 10 micromolar RA in the dark for 3-10 days. SHSY5Y cells possess small processes in an undifferentiated state, and after treatment with RA, the cells developed long neurites, resembling a neuronal phenotype. Total RNA was isolated with Tri-Reagent. Expression profiles of the target genes were determined by semi-quantitative RT-PCR. According to the results, Bcl-2 and CCND1 gene expression levels were increased, while URG4/URGCP and Bax gene expression was decreased in RA treated cells compared to the control cells. Our preliminary results suggest that RA may induce cell proliferation and escape apoptosis using a novel pathway by the URG4/URGCP gene. Further investigations are needed to clarify more direct transcriptional targets of RA signaling and the interaction of RA pathways with other pro-regenerative signals.
[show abstract][hide abstract] ABSTRACT: Hepatocellular carcinoma (HCC) originates from liver cells and is one of the most common malignant cancers in the world. microRNAs (miRNA), are single strand non-coding RNA molecules with the length of 18-25 nucleotides. miRNAs play an important role in the development of HCC, i.e., miRNAs have a significant impact on multistep hepatocellular carcinogenesis including cellular migration and invasion. URG4/URGCP (up-regulated gene-4/upregulator of cell proliferation) is up-regulated in the presence of HBxAg and has been identified and characterized by Satiroglu-Tufan et al. The full-length URG4/URGCP is 3.607 kb. Overexpression of URG4/URGCP in the presence of HBV X protein may function as a putative oncogene that significantly contributes to multi-step hepatocarcinogenesis. In this study, we aimed to investigate potential miRNA expression changes in HepG2 cell line model system in the presence of URG4/URGCP and in the absence of URG4/URGCP, which was suppressed by RNA interference. To functionally characterize URG4/URGCP, independent cultures of HepG2 cells were stably transfected with pcDNA3 or pcDNA3-URG4/URGCP. Relative quantification of whole genome miRNAs was analyzed by RT-PCR using human whole genome miRNA qPCR profiling kits. Among the 1,034 human miRNAs investigated by the arrays, 77 miRNAs were up-regulated and nine miRNAs were down-regulated in the presence of URG4/URGCP. In conclusion, we have analyzed miRNA profiles in HepG2 cells in presence or absence of URG4/URGCP gene using RNA interference. Some of these miRNAs may play roles in URG4/URGCP gene related disease development through the regulation of different signaling pathways.
[show abstract][hide abstract] ABSTRACT: This study was undertaken to evaluate the expression of DMBT1 in bladder cancer and its correlation with clinico-pathological parameters analyzed in bladder carcinoma patients. We investigated DMBT1 in 56 paraffin embedded specimens of transitional cell carcinoma of the urinary bladder. We assessed DMBT1 gene expression at mRNA level by RT-PCR. Our results show 100% expression of DMBT1 in bladder carcinoma samples. Due to this preliminary results; gene expression was compared to tumor grade, and a significant difference was detected between grade 1 and 3 (p = 0.028). The down-regulation of DMBT1 gene expression in carcinomas suggests the possible role in bladder cancer.
[show abstract][hide abstract] ABSTRACT: Bladder cancer is the fifth most commonly diagnosed cancer in the United States, where the majority of tumors are transitional cell carcinoma. Deleted in malignant brain tumors 1 (DMBT1) gene is located at chromosome 10q25.3-q26.1. DMBT1 gene expression has yet to be investigated in patients with bladder cancer. Runt-related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene which is localized on the chromosome 1p36. RUNX3 gene expression in bladder carcinogenesis is particularly unknown. We aimed to evaluate DMBT1 and RUNX3 gene expression profiles in bladder cancer and how their expressions could be related to carcinogenesis in the bladder and their correlation with clinicopathological parameters. Fifty-six paraffin embedded specimens of transitional cell carcinoma of the urinary bladder were used. Total RNA was extracted from bladder specimens and cDNA was synthesized. The quantification of DMBT1 and RUNX3 mRNAs were succeeded according to the manufacturers' instructions by using RT-PCR. DMBT1 and RUNX3 gene expressions were identified in 100% of bladder carcinoma samples. No significant association was found in these genes expression levels when compared to sex and age. RUNX3 gene expression was decreased non-significantly in high-grade tumors. When DMBT1 gene expression was compared to tumor grades, a significant decrease was detected between grade I and III (P = 0.028). Disruption of expression in relation to tumor suppressors like DMBT1 and RUNX3 genes was associated with bladder cancer. Furthermore, detailed studies including these genes should be performed in protein levels and used more patient specimens in a large scale study.
[show abstract][hide abstract] ABSTRACT: Bladder cancer is the most frequent cancer of the urinary system. Fibroblast growth factor receptors (FGFR) belong to the tyrosine kinase family and have important roles in cell differentiation and proliferation and embryogenesis. FGFR3 is located on chromosome 4p16.3, and missense mutations of FGFR3 are associated with autosomal dominant human skeletal disorders and have some oncogenic effects. We examined the incidence of FGFR3 thanatophoric dysplasia mutations located in exon 7, A248C and S249C, and in exon 10, G372C and T375C, and their correlation with clinical-pathological parameters in bladder carcinoma patients. Fifty-six paraffin-embedded specimens of transitional cell carcinoma of the urinary bladder were included in this study. Analysis of FGFR3 thanatophoric dysplasia mutations located in exon 7, A248C and S249C, and in exon 10, G372C and T375C, was performed by PCR-restriction fragment length polymorphism (RFLP) analysis and DNA sequencing. FGFR3 thanatophoric dysplasia mutations located in exon 7, A248C and S249C, and in exon 10, G372C and T375C, were detected in 33 of the 56 patients (heterozygous mutant). Among the 56 transitional cell carcinomas, missense point mutations were detected in seven of them at codon A248C, 28 of them at codon S249C, and three of them at codon T375C, similar to data from previous reports. When the results of the FGFR3 thanatophoric dysplasia mutations located in exon 7, A248C and S249C and in exon 10, G372C and T375C, were analyzed one by one or as a group, despite the findings of previous research reports, our data suggest that these mutations are detected homogenously regardless of the tumor classification and tumor grade.
[show abstract][hide abstract] ABSTRACT: Up-regulated gene 4 (URG4), stimulated by HBxAg, is a novel gene located on chromosome 7 (7p13). The full-length URG4 clone is 3.607 kb and encodes a polypeptide of 922 amino acids, with a molecular weight of 104 kDa (GeneID: 55665). It promotes cell growth, growth factor-independent survival, and anchorage-independent growth in HepG2 cells, and it accelerates tumor formation in nude mice. Hence, URG4 may be a natural effector of HBxAg and a putative oncogene that contributes to multi-step hepatocarcinogenesis. Cyclin D1 is frequently over-expressed in hepatocellular carcinoma, exhibiting a number of malignant phenotypes. We found that down-regulation of URG4 through RNA interference-mediated silencing suppressed cell proliferation in HepG2 cells. Over-expression of URG4 up-regulated cyclin D1 mRNA expression, whereas RNA interference-mediated URG4 silencing diminished cyclin D1 mRNA expression in HepG2 cells. The data suggest that URG4 may play an important role in the development of hepatocellular carcinoma by partially regulating the expression of cyclin D1 and has potential for use as a therapeutic target for hepatocellular carcinoma.
[show abstract][hide abstract] ABSTRACT: Up-regulated gene 4 (URG4) is a novel gene that may be associated with the onset of tumorigenesis and cell cycle regulation. The present study examined for the first time the expression of URG4 in osteosarcoma, which is one of the most rapidly growing sarcomas, and investigated its prognostic value in both disease-free and overall survival of the patients.
The expression of URG4 in osteosarcoma tissues was examined by immunohistochemistry in 46 patients who underwent surgical operation for osteosarcoma; the correlation of URG4 with proliferating cell nuclear antigen index (PCNA) and microvessel count (MVC) was analysed, and the prognostic value of URG4 in patients was investigated.
URG4 was highly expressed in 40 of 46 (86.96%) osteosarcoma specimens with cytoplasmic staining, and also increased in the specimens with recurrence (p < 0.05) and metastasis (p < 0.05). The mean disease-free survival and overall survival were 50.25 and 54.08 months for patients with over-expressed URG4, compared with 69.54 and 70.01 months for those with low expression. URG4 was also found to be highly related with PCNA, while no significant relationship was found between URG4 and MVC.
URG4 may play important roles in the development of osteosarcoma, and might be a useful molecular marker for predicting the prognosis of osteosarcoma.
[show abstract][hide abstract] ABSTRACT: Pseudoachondroplasia (PSACH) is an autosomal-dominant osteochondrodysplasia due to mutations in the gene encoding cartilage oligomeric matrix protein (COMP). Clinical diagnosis of PSACH is based primarily on family history, physical examination, and radiographic evaluation, and is sometimes extremely difficult, particularly in adult patients. Genetic diagnosis based on DNA sequencing, on the other hand, can be expensive, time-consuming, and intensive because COMP mutations may be scattered throughout the gene. However, there is evidence that decreased plasma COMP concentration may serve as a diagnostic marker in PSACH, particularly in adult patients. Here, we report the serum and/or plasma COMP concentration-based differential diagnosis of a family with affected adult members. The mean serum and/or plasma COMP concentrations of the three affected family members alive (0.69+/-0.15 and/or 0.81+/-0.08 microg/ml, respectively) were significantly lower than those of an age-compatible control group of 21 adults (1.52+/-0.37 and/or 1.37+/-0.36 microg/ml, respectively; P<0.0001). Bidirectional fluorescent DNA sequencing-based genetic diagnosis of these patients revealed a heterozygous mutation for the nucleotide change 1532A>G in exon 14 of the COMP gene, resulting in a substitution of amino acid 511 from aspartic acid to glycine in COMP. Thus, serum and/or plasma COMP concentration may be suggested as an additional diagnostic marker to aid clinical and radiographic findings in suspected cases of PSACH.
European Journal of HumanGenetics 11/2007; 15(10):1023-8. · 4.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the apoptotic process of cells within the intestinal metaplasia areas co-localizing with chronic gastritis and gastric carcinomas and to analyze the involvement of proteins regulating apoptosis in the process of intestinal metaplasia related gastric carcinogenesis.
Forty-two gastric carcinoma and seventeen chronic gastritis cases were included in this study. All cases were examined for the existence of intestinal metaplasia. Ten cases randomly selected from each group were processed for TUNEL assay. TUNEL positive cells within the intestinal metaplasia areas, co-localizing either to gastric carcinoma or chronic gastritis, were counted and converted to apoptotic indices. In addition, p53, bcl-2 and bax expression patterns within these tissues were analyzed on the basis of immunohistochemistry.
Twenty-eight of the cases were intestinal and 14 of the cases were diffuse type adenocarcinomas. 64% (27/42) of the gastric carcinoma cases had intestinal metaplasia. Intestinal metaplasia co-localized more with intestinal type carcinomas compared with diffuse type carcinomas [75% (21/28) vs 42% (6/14), respectively; P<or=0.05]. The mean apoptotic index in tumor cells was 0.70+/-0.08. The mean apoptotic index in intestinal metaplasias co-localizing to tumors was significantly higher than that of intestinal metaplasias co-localizing to chronic gastritis (0.70+/-0.03 vs 0.09+/-0.01, respectively; P<or=0.05). p53 positivity was not observed in areas of intestinal metaplasia adjacent to tumors or chronic gastritis. Intestinal metaplasia areas adjacent to tumors showed lower cytoplasmic bcl-2 positivity compared to intestinal metaplasia areas adjacent to chronic gastritis [55.5% (15/27) vs 70.5% (12/17), respectively]. On the other hand, intestinal metaplasia areas adjacent to tumors showed significantly higher cytoplasmic bax positivity compared to intestinal metaplasia areas adjacent to chronic gastritis [44.4% (12/27) vs 11.7% (2/17), respectively; P<or=0.05].
Existence of apoptotic cells on the basis of TUNEL positivity is shown in intestinal metaplasias co-localizing to both diffuse and intestinal type gastric cancers in this study. Our results also suggested bax expression dependent induction of apoptosis especially in intestinal metaplasia areas adjacent to tumors. These findings strongly support the involvement of apoptotic mechanisms in the process of gastric carcinogenesis especially in the transition from intestinal metaplasia to gastric cancer. It may be suggested that induction of apoptosis in intestinal metaplasia areas adjacent to tumors may involve different mechanisms than induction by chronic inflammation.
World Journal of Gastroenterology 06/2007; 13(23):3183-8. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: A 45,X karyotype is one of the common chromosomal abnormalities characterized by short stature, lack of development of secondary sexual characteristics, webbed neck and cubitus valgus. This phenotype was described by Turner in 1938 and was called Turner syndrome (TS). About 40-60% of the patients with TS phenotype have a 45,X karyotype, the rest either have a structurally abnormal X or Y chromosome or mosaicism with a second cell line. Determination of Y chromosome derivatives in patients with a 45,X karyotype is important for the management of these patients due to increased risk of gonadoblastoma. Low level mosaicism of Y chromosome may be missed by cytogenetic methods. The aim of our study is to analyze cryptic Y chromosome derivatives using Y specific sequences in 40 Turkish patients with a pure 45,X karyotype. Fourteen different Y specific sequences along the Y chromosome were selected for the detection of cryptic Y chromosome material by PCR analysis. The present study demonstrated that 2 patients with a 45,X karyotype (5%) have Y specific sequences except sex related region Y (SRY). One of them had displayed enhanced virilisation whereas other showed no virilisation. In conclusion, it has been found by PCR analysis that 5% of patients with a 45,X karyotype have Y chromosome sequences in the absence of any marker chromosome by cytogenetic analysis. The data also suggest that the patients with a 45,X karyotype should be analyzed for the presence of Y chromosome derivatives by sensitive methods, such as PCR, in order to calculate the future risk of developing gonadoblastoma.
The Tohoku Journal of Experimental Medicine 04/2007; 211(3):243-9. · 1.37 Impact Factor
[show abstract][hide abstract] ABSTRACT: Achondroplasia is the most common genetic form of dwarfism inherited as an autosomal dominant disorder. Individuals affected with achondroplasia have impaired ability to form bone from cartilage (endochondral bone formation). Homozygous achondroplasia is a neonatal lethal condition. The vast majority of patients with achondroplasia have a G-to-A transition at position 1138 of the fibroblast growth factor receptor 3 (FGFR3) cDNA sequence, resulting in the Gly-to-Arg substitution at position 380 of the FGFR3 protein. This mutation has been diagnosed by SfcI digestion of amplified genomic DNA. However, it has also been demonstrated that the SfcI digestion protocol does not consistently distinguish between DNA samples heterozygous and homozygous for the G1138A substitution. This study was designed to improve the molecular diagnosis based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques for the FGFR3 G1138A mutation. The newly designed forward primer contains one mismatch (G at position 1136) from the FGFR3 cDNA sequence (A at position 1136), thereby creating a PstI site (CTGCAG at positions 1134 to 1139) in the amplified DNA from alleles containing the G1138A mutation. The PCR-RFLP technique based on the PstI digestion of amplified genomic DNA with a novel forward primer shows 100% accuracy in diagnosis of the G1138A mutation in heterozygous and homozygous individuals.
The Tohoku Journal of Experimental Medicine 03/2006; 208(2):103-7. · 1.37 Impact Factor
[show abstract][hide abstract] ABSTRACT: While the correlation between the CAG repeat length of the androgen receptor (AR) gene and idiopathic male infertility is still unclear, ethnic background of the population studied may play an important role in this association. The objective of this study was to determine whether changes in the CAG repeat length are associated with spermatogenic defects in Turkish infertile men. Reproductive hormone concentrations and the CAG repeat length in exon 1 of the AR gene in 47 idiopathic infertile men and 32 fertile controls were analyzed. The mean serum luteinising hormone (LH) and follicle stimulating hormone (FSH) levels were significantly higher in the infertile group than those of the control group (p < 0.0001 for both comparisons), whereas the mean serum testosterone level in the infertile group did not differ significantly from that in the control group (p = 0.16). The mean CAG repeat length of the AR gene in the infertile group did not differ significantly from that in the control group (22.28 +/- 0.37 vs 22.41 +/- 0.54, respectively; p = 0.84). In addition, the frequency of having a CAG repeat number (> or = 24) was also comparable between the infertile patients and fertile controls (31.9% vs 40.6%, respectively; p = 0.21). In conclusion, reproductive hormones with elevated LH and FSH, and normal or low testosterone levels were suggestive of partial impairment of testicular function. However, no statistically significant relationship between the length of the CAG repeat and idiopathic impaired sperm production was observed in the Turkish population studied. These results support the findings of previously published European studies, but are contrary to the findings from Caucasian and North American population studies. Thus, ethnicity and genetic backgrounds seem to be important in this association, and studies from a variety of different ethnic and genetic backgrounds using comparable patient subgroups are valuable to further evaluate this association.
The Tohoku Journal of Experimental Medicine 07/2005; 206(2):105-15. · 1.37 Impact Factor
[show abstract][hide abstract] ABSTRACT: Angiogenesis, the formation of new blood vessels, is essential for tumor growth, progression and metastasis. The development of agents that target tumor vasculature is ultimately dependent on the availability of appropriate preclinical screening assays. The chorioallantoic membrane (CAM) assay is well established and widely used as a model to examine angiogenesis, and anti-angiogenesis. This review 1) summarizes the currently used angiogenesis assays and the importance of CAM model among them; 2) summarizes the current knowledge about the development and structure of the CAM's capillary bed; 3) reports findings regarding the role played by molecular signaling pathways in angiogenesis process; 4) discusses the use, advantages and limitations of the CAM as a model for studying tumor angiogenesis and invasiveness, as well as development of angiogenic and/or anti-angiogenic agents; 5) discusses the importance of standardization of the major methodologies for all aspects of the use of the CAM in angiogenesis-related studies; 6) and finally, summarizes major findings regarding the agents developed by the use of CAM model in the study of tumor angiogenesis, invasion and development of anti-angiogenic agents.
Current Cancer Drug Targets 07/2005; 5(4):249-66. · 4.00 Impact Factor
[show abstract][hide abstract] ABSTRACT: The mechanisms of teratogenic action of ethanol (EtOH) were investigated by testing the hypothesis that all-trans-retinoic acid and/or alpha-tocopherol ameliorates ethanol-induced embryonic growth retardation. Chicken embryos were explanted in shell-less cultures and a single dose of EtOH (15, 30, or 50%) or 50% EtOH with either all-trans-retinoic acid (10(-8)M) or alpha-tocopherol (0.05 M) or a mix of all-trans-retinoic acid (10(-8)M) and alpha-tocopherol (0.05 M) was applied to the center of the blastodisc. EtOH significantly increased the mortality rate and induced growth retardation in a dose-dependent manner. In addition, EtOH increased malondialdehyde (MDA) levels, an indicator of oxidative stress and cell damage, in a dose dependent manner. All-trans-retinoic acid, the active form of Vitamin A, and/or alpha-tocopherol, an antioxidant, co-treatment with EtOH significantly diminished both the EtOH-induced mortality and growth retardation. However, only alpha-tocopherol co-treatment reduced the MDA levels. Thus, the mechanisms of teratogenic action of EtOH appear to involve initiation of oxidative stress as well as perturbation of retinoic acid (RA) signaling. It also appears likely that these mechanisms work independently of each other.
[show abstract][hide abstract] ABSTRACT: A large number of archival paraffin-embedded tissue banks have been established during diagnostic surgical pathology, forming a precious resource of tissues for retrospective molecular studies of cancer and a variety of other diseases. Extraction of DNA from formalin-fixed paraffin-embedded tissue samples was previously accomplished. However, this procedure is labor intensive, time-consuming and expensive. This study demonstrated the successful use and optimization of a rapid, reliable and effective protocol for DNA amplification directly from paraffin-embedded tissue eliminating the deparaffinization and DNA isolation steps. In the course of this study effectiveness of a commercially available, ready-to-use PCR master mix kit was also tested. Once the presented protocol for DNA amplification is applied correctly, large quantities of paraffin-embedded material stored in our pathology departments will be available for molecular diagnostics and research.
[show abstract][hide abstract] ABSTRACT: The effect of ethanol (EtOH) exposure on extraembryonic vascular development was examined using the chick embryo area vasculosa (AV) in shell-less culture. Embryos were placed in cultures at Hamburger Hamilton (HH) stage 11/12 and a single dose of EtOH (10, 30 or 50%) was applied to the center of the blastodisc. Untreated/sodium-chloride-treated controls showed normal embryonic growth and well-developed extraembryonic vessels at 24/48 h of treatment. At doses of 30 and 50%, the mortality rate was significantly increased, and survivors demonstrated significant growth retardation and inhibition of normal vascular development in a dose-dependent manner. Immunostaining for vascular endothelial growth factor (VEGF) showed that mesenchymal cells continued to differentiate into angioblasts to form blood islands, but their assembly into primitive vessels was perturbed in a dose-dependent manner. Northern blot analyses of basic fibroblast growth factor, VEGF, Flt-1 and Flk-1 mRNA expression supported these findings and showed a dose-dependent decrease in EtOH-treated cultures compared to controls. Co-treatment with alpha-tocopherol (0.05 M) or all-trans-retinoic acid (10(-8) M) significantly decreased the mortality rate and improved both embryonic growth and extraembryonic vascular development in the cultures. On the other hand, almost all embryos treated with 10% EtOH survived the first 48 h after treatment. However, the complexity of the vascular tree measured as the relative vasculogenesis index, the surface area of the AV and the mRNA expression of vasculogenic molecules were increased during the first 24 h. This acute effect disappeared 48 h after treatment and the vascular tree continued to develop parallel to the controls. No significant growth retardation was observed in this group. These results suggest that, in terms of extraembryonic vascular development, an early, single, low-dose EtOH exposure may have an acute, short-term positive effect, whereas moderate- or high-dose EtOH exposure may severely perturb this process disabling the necessary absorption of the nutrients for the embryo to develop properly. The mechanisms of action of EtOH on extraembryonic vascular development may involve the establishment of reactive oxygen species, resulting in the initiation of oxidative stress and perturbation of retinoic acid signaling and alterations in the expression of growth-regulatory vasculogenic factors and their receptors.