Ets-1 mRNA Research Articles

Clinical implications of expression of ETS-1 in relation to angiogenesis in ovarian cancers.

ETS-1 has been identified as a transcription factor involved in tumor angiogenesis, which is essential for the growth, invasion, and metastasis of solid tumors. This result prompted us to study whether ETS-1 works as an angiogenic mediator in ovarian cancers. Immunohistochemical staining revealed that ETS-1 was expressed in vascular endothelial cells and in cancer cells of ovarian cancers. There was a significant correlation between microvessel counts and both ETS-1 histoscores and ets-1 mRNA levels in ovarian cancers. Both ETS-1 histoscores and ets-1 mRNA levels increased with the progression of ovarian cancers. Furthermore, the 24-month survival rate of 30 patients with high ets-1 (high ETS-1 histoscores and high ets-1 mRNA levels) was 30%, while that of 30 other patients with low ets-1 (low ETS-1 histoscores and ets-1 mRNA levels) was 70%. There was a significant difference between the 24-month survival rates of the 30 patients with high ets-1 and the 30 with low ets-1. This indicates that ETS-1 might act as an angiogenic mediator in, and be a prognostic factor for, ovarian cancers.

Stimulation of in vitro angiogenesis by nitric oxide through the induction of transcription factor ETS-1

The aim of this study was to examine whether transcription factor ETS-1, which is responsible for the expression of metalloproteinases and integrin β 3, is implicated in the induction of nitric oxide (NO)-induced angiogenesis. Bovine aortic endothelial cells were cultured on type I collagen gel to measure the length of the formed tube-like structure, which is a marker for in vitro angiogenesis. The addition of S-nitroso- N-acetylpenicillamine (SNAP), an NO-donor, to confluent endothelial cells stimulated the formation of the tube-like structure, with disappearance of covered endothelial cell monolayers. Another NO-donor 2,2′-(hydroxynitrosohydrazono)bis-ethanamine (NOC 18) also induced the formation of the tube-like structure. In contrast to the induction of the formation of the tube-like structure by SNAP, it reduced cell proliferation. SNAP and NOC 18 also increased the expression of the ets-1 mRNA level in a concentration-dependent manner. The maximum expression was observed at 2 h after their addition. Moreover, the SNAP-induced in vitro angiogenesis, ets-1 mRNA expression and ETS-1 protein expression were strongly reduced by the treatment with ets-1 antisense oligonucleotide. These results strongly suggest that NO stimulates in vitro angiogenesis through the induction of ETS-1 expression. NO appears to stimulate endothelial cell differentiation to the angiogenic phenotype via the induction of ETS-1 transcription factor.

Expression of ETS-1 Related to Angiogenesis in Uterine Endometrium during the Menstrual Cycle

ETS-1 has been identified as a transcription factor for angiogenesis, which is essential for the development and growth of the uterine endometrium. This characteristic prompted us to study whether ETS-1 functions as an angiogenic mediator in uterine endometrium. Immunohistochemical staining revealed that the localization of ETS-1 was similar to that of vascular endothelial cells. There was a significant correlation between microvessel counts and both ETS-1 histoscores and ets-1 mRNA levels in uterine endometrium. The ETS-1 histoscores and ets-1 mRNA levels increased in the proliferative phase, reached a peak during peri-ovulation and decreased in the secretory phase. Furthermore, the ETS-1 histoscores and ets-1 mRNA levels correlated with vascular endothelial growth factor (VEGF) levels in the proliferative phase. This indicates that ETS-1 might be an angiogenic mediator in uterine endometrium linked to VEGF in the proliferative phase.

Angiogenic property of hepatocyte growth factor is dependent on upregulation of essential transcription factor for angiogenesis, ets-1.

Although hepatocyte growth factor (HGF) is an angiogenic growth factor, it is still unclear how it exerts its angiogenic effects. Thus, we focused on the role of an essential transcription factor for angiogenesis, ets-1. In this study, we addressed the following specific questions: (1) what genes responsible for angiogenesis can be regulated by HGF and (2) whether upregulation of gene expression for angiogenesis is dependent on ets-1. In human endothelial cells, HGF significantly stimulated the matrix-degrading pathway, such as the production of matrix metalloprotease-1 (MMP-1) through its specific receptor, c-met. In addition, HGF also significantly increased HGF itself and its specific receptor, c-met. Moreover, HGF significantly increased the transcription activity and mRNA expression of ets-1 in a time-dependent manner. Importantly, transfection of antisense ets-1 oligodeoxynucleotides (ODN) resulted in a significant reduction in MMP-1, HGF and c-met. Interestingly, HGF also stimulated ets-1 mRNA in vascular smooth muscle cells, similar to endothelial cells. Of importance, transfection of antisense ets-1 ODN resulted in a significant decrease in vascular endothelial growth factor (VEGF) and HGF expression, whereas HGF stimulated both HGF and VEGF expression. Moreover, in vivo transfection of ets-1 antisense ODN resulted in an inhibition of angiogenesis induced by the HGF gene in a rat ischemic hindlimb model. Here, we demonstrated that HGF stimulated the expression of MMP-1, VEGF, HGF itself, and c-met in human endothelial cells and vascular smooth muscle cells. Upregulation of angiogenesis-related genes was largely dependent on the induction of ets, especially ets-1. These data provide new information about the mechanisms of angiogenesis.

ETS2 is involved in protein kinase C-activated expression of granulocyte–macrophage colony-stimulating factor in human non-small lung carcinoma cell line, A549

Granulocyte–macrophage colony-stimulating factor (GM-CSF) is a cytokine expressed in the non-small lung carcinoma cells (NSCLC). However, transcriptional regulation of GM-CSF is not well characterized in NSCLC. In this study we found that two cis-acting ETS family consensus sites are important for transcriptional regulation of GM-CSF in A549 human lung carcinoma cells. These two sites are located separately at around −40 and −100 bp from the transcription start site. Results of transient transfection assays with A549 cells indicated that ETS2 had a strong positive effect on GM-CSF promoter activity. Furthermore, this activity was enhanced by protein kinase C activator, phorbol 12-myristate 13-acetate (PMA), in an ETS consensus-dependent manner, while PMA could also enhance the expression level of ETS2. The protein kinase C inhibitors decreased GM-CSF promoter activity induced by the protein kinase C activator PMA. We also found that antisense ETS2 mRNA decreased PMA-induced GM-CSF promoter activity, supporting the possibility that ETS2 is involved in protein kinase C-induced GM-CSF transcriptional function. Endogenous expression of GM-CSF mRNA was increased by ETS2 transfection and the increased expression was further enhanced by PMA. These data indicate that GM-CSF is up-regulated by ETS2, a target of protein kinase C.

Ets-1 gene expression in patients with thymoma.

The Ets-1 protooncogene transcription factor is involved in several cellular functions, including the activation of several proteases, and reportedly plays an important role in carcinoma invasion and metastasis. We hypothesize that Ets-1 mRNA expression could be a predictor of thymoma development and invasion. Subjects were 37 patients with thymoma whose mRNA expression was quantified by real-time reverse-transcription polymerase chain reaction (RT-PCR) using LightCycler, a microvolume multisample fluorimeter. No significant difference was found in Ets-1 mRNA expression for gender, age, or pathological subtype. Ets-1 mRNA expression in tumor tissues from stage II-IV thymoma (25.311 +/- 42.336) was more elevated than in that from stage I thymoma (2.097 +/- 4.492) (p = 0.0374). Ets-1 mRNA expression may thus serve as a marker of higher thymoma stages. With use of the Light Cycler RT-PCR assay, Ets-1 expression may play an important role in the extension and progression of thymoma as in other cancers. Further study and longer follow-up are, however, needed to confirm the Ets-1 impact on biological tumor behavior.

Clinical implications of expression of ETS-1 related to angiogenesis in uterine cervical cancers

BackgroundAngiogenesis is essential for development, growth and advancement of solid tumors. ETS-1 has been recognized as a candidate for tumor angiogenic transcription factor. This prompted us to study the clinical implications of ETS-1-related angiogenesis in uterine cervical cancers. Patients and methodsFifty patients underwent curative resection for uterine cervical cancers. The patients’ prognoses were analyzed with a 24-month survival rate. In the tissue of 60 uterine cervical cancers, the levels of ets-1 mRNA, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor (PD-ECGF) and interleukin (IL)-8 were determined by competitive reverse transcription–polymerase chain reaction using recombinant RNA and enzyme immunoassay, and the localization and counts of microvessels were determined by immunohistochemistry. ResultsThere was a significant correlation between microvessel counts and ets-1 gene expression levels in uterine cervical cancers. Immunohistochemical staining revealed that the localization ofETS-1 was similar to that of vascular endothelial cells. The level of ets-1 mRNA correlated with the levels of PD-ECGF and IL-8 among angiogenic factors. Furthermore, the prognosis of the 25 patients with high ets-1 mRNA expression in uterine cervical cancers was extremely poor, while the 24-month survival rate of the other 25 patients with low ets-1 mRNA expression was 92%. ConclusionsETS-1 might be a prognostic indicator as an angiogenic mediator in uterine cervical cancers.

Clinical implications of expression of ETS-1 related to angiogenesis in uterine endometrial cancers

BackgroundAngiogenesis is essential for development, growth and advancement of solid tumors. During angiogenesis, ETS-1 is strongly expressed in vascular endothelial cells and the adjacent interstitial cells, while the inhibition of ETS-1 expression leads to suppression of angiogenesis. This prompted us to study the clinical implications of ETS-1 in relation to angiogenesis in uterine endometrial cancers. Patients and methodsSixty patients underwent resection for uterine endometrial cancers. From the tissues of 60 uterine endometrial cancers, the levels of ets-1 mRNA, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor(PD-ECGF) and interleukin (IL)-8 were determined by competitive RT–PCR using recombinant RNA and enzyme immunoassay, and the localization and counts of microvessel were determined by immunohistochemistry. ResultsThere was a significant correlation between microvessel count and ets-1 gene expression levels in uterine endometrial cancers. Immunohistochemical staining revealed that the localization of ETS-1 was similar to that of vascular endothelial cells. The level of ets-1 mRNA tended to increase with increasing disease stage. Furthermore, the level of ets-1 mRNA correlated with levels of VEGF in well-differentiated adenocarcinomas (G1) and of bFGF in moderately differentiated adenocarcinomas (G2) and poorly differentiated adenocarcinomas (G3). ConclusionsETS-1 is a possible angiogenic mediator in uterine endometrial cancers.

Ets-1 Upregulates Matrix Metalloproteinase-1 Expression through Extracellular Matrix Adhesion in Vascular Endothelial Cells

Ets-1 is a transcription factor regulating the expression of matrix-degrading proteinases and is believed to play a critical role in cell migration and tumor invasion. The aim of this study is to investigate the direct induction of ets-1 with consequential upregulation of collagenase-1 (MMP-1) by cell adhesion to extracellular matrix and to identify intracellular signal transduction pathways involved in ets-1 induction in cultured endothelial cells. The expressions of ets-1 mRNA and protein as well as MMP-1 protein were induced by cell adhesion to type I collagen and antisense ets-1 oligonucleotides impaired that MMP-1 expression. In addition, protein tyrosine kinase (PTK) and protein kinase C (PKC) inhibitors abrogated their induction, showing the suppression of focal adhesion kinase phosphorylation. These results suggest that ets-1 induced by cell adhesion to extracellular matrix directly upregulates MMP-1 expression via PTK and PKC activation in cultured endothelial cells.

Ets-1 mRNA expression in effusions of serous ovarian carcinoma patients is a marker of poor outcome.

Ets-1 proto-oncogene is a transcription factor with a role in the activation of metastasis-associated molecules. We recently found that Ets-1 mRNA expression in solid tumors is a marker of poor prognosis in ovarian carcinoma. The objective of this study was to compare the expression of Ets-1 mRNA in effusions and primary and metastatic tumors of serous ovarian carcinoma patients and to evaluate its prognostic role in effusions. Sections from 67 malignant effusions and 90 primary and metastatic lesions were evaluated for expression of Ets-1 using mRNA in situ hybridization. Expression of Ets-1 mRNA was detected in carcinoma cells in 24 of 67 (36%) effusions. Expression in cancer cells was similar in peritoneal and pleural effusions. In solid lesions Ets-1 expression was detected in both tumor cells and stromal cells in 34 of 90 (38%) lesions. Ets-1 expression in tumor cells showed a strong association with that of stromal cells (p <0.001). Ets-1 expression in effusions showed an association with mRNA expression of basic fibroblast growth factor, previously studied in this patient cohort (p = 0.019). Ets-1 expression in solid lesions showed an association with mRNA expression of vascular endothelial growth factor (p <0.001 for both carcinoma and stromal cells), basic fibroblast growth factor (p = 0.007 for carcinoma cells, p = 0.006 for stromal cells), and interleukin-8 (IL-8) (p = 0.001 for tumor cells). Ets-1 mRNA showed upregulation in metastases when compared with effusion specimens (p = 0.028). In univariate survival analysis Ets-1 expression in carcinoma cells in effusions correlated with poor survival (p = 0.003). Our findings confirm the role of Ets-1 as a novel prognostic marker in advanced-stage ovarian carcinoma and extend it to effusion specimens. The elevated expression in solid metastases supports a central role in tumor progression as well. The association between Ets-1 mRNA expression and the expression of angiogenic genes, documented also in our previous study, points to the close link between these molecules, in agreement with the role of angiogenic genes in the transcriptional activation of Ets-1. The identical phenotype of carcinoma cells in pleural and peritoneal effusions provides further evidence for our theory that cells at these sites share similar genotypic and phenotypic profiles.

Clinical significance of matrix metalloproteinase-7 and Ets-1 gene expression in patients with lung cancer.

Matrix metalloproteinase-7 (MMP-7) is a member of the MMP family and has a wide variety of substrate spectra. Ets domain transcription factors are reported to play an important role in carcinoma invasion and metastasis. The regulatory role of Ets-1 has been shown in several MMPs. We have hypothesized that MMP-7 and Ets-1 mRNA levels could be predictors of the development and invasion of lung cancer. The study included 73 lung cancer cases. The mRNA levels were quantified by real-time reverse transcription-polymerase chain reaction (RT-PCR) using a LightCycler. No significant difference in MMP-7 and Ets-1 mRNA levels was found among gender, age, and pathological subtype. The MMP-7 mRNA levels were elevated in tumor tissues from stage II-IV lung cancer (1.629 +/- 2.267) compared to those from stage I lung cancer (0.762 +/- 1.463) (P = 0.0290). There was a tendency toward higher MMP-7 mRNA expression levels in tumors with lymph node metastasis (1.728 +/- 2.432) compared to those without lymph node metastasis (1.141 +/- 1.838) (P = 0.1076). Thus, MMP-7 mRNA levels may serve as a marker of higher stages in lung cancer. No significant difference in Ets-1 mRNA levels was found among clinical stages and T-status. The Ets-1 mRNA levels were elevated in tumors from N2 patients (7.512 +/- 13.306) compared to those from N0 patients (2.525 +/- 4.719) (P = 0.0209). Ets-1 mRNA levels showed a positive correlation with MMP-7 expression (P = 0.0042). Using the LightCycler RT-PCR assay, the determination of MMP-7 and Ets-1 mRNA levels might provide a potential marker for advanced lung cancer. However, further studies and a longer follow-up are needed to confirm the impact of MMP-7 in the biological behavior of the tumor.

Hepatocyte growth factor induces collagenase (matrix metalloproteinase-1) via the transcription factor Ets-1 in human hepatic stellate cell line

Background/Aims : Although hepatocyte growth factor recently has been shown to decrease hepatic fibrosis in animal models, the molecular mechanisms of this effects remain to be elucidated. We investigated regulation of collagenase expression by hepatocyte growth factor in hepatic stellate cells. Methods : A human hepatic stellate cell line, LI90, was treated with hepatocyte growth factor. Expression of collagenase, 72 kDa gelatinase, procollagen α1(I), tissue inhibitor of matrix metalloproteinase-1, transforming growth factor- β1, or Ets-1, and carboxyterminal telopeptide of type I collagen was examined. Ets-1 binding activity was determined by gel mobility shift assay, collagenase promoter activity was evaluated by reporter gene assay. LI90 cells were also transfected with Ets-1 antisense oligonucleotides with or without hepatocyte growth factor. Results : Hepatocyte growth factor increased expression of collagenase mRNA and protein, and an increase in Ets-1 mRNA preceded the increase in collagenase mRNA. Collagenase activity and protein, and a degradation product of type I collagen were increased in the medium. Nuclear extracts from treated LI90 cells also showed increased Ets-1 binding activity. Hepatocyte growth factor and cotransfection of Ets-1 enhanced promoter activity of collagenase gene. Furthermore, treatment of LI90 cells with Ets-1 antisense oligonucleotides downregulated basal and hepatocyte growth factor-induced Ets-1 and collagenase mRNA expression. Conclusions : Collectively, the results suggest that hepatocyte growth factor increases collagenase expression in hepatic stellate cells via the Ets-1 transcription factor-dependent manner.

Cyclic changes in expression of mRNA of vascular endothelial growth factor, its receptors Flt-1 and KDR/Flk-1, and Ets-1 in human corpora lutea

Objective: To evaluate the expression of mRNA of vascular endothelial growth factor (VEGF), its receptors Flt-1 and KDR/Flk-1, and Ets-1 in human corpora lutea.Design: Prospective laboratory study.Setting: University hospital in Japan.Patient(s): Women with regular menstrual cycles who underwent hysterectomy.Intervention(s): Fifteen corpora lutea were obtained during hysterectomy (5 in the early luteal phase, 5 in the mid-luteal phase, and 5 in the late luteal phase).Main Outcome Measure(s): Expression of VEGF, Flt-1, KDR/Flk-1, and Ets-1 in human corpora lutea on northern blot analysis or immunohistochemistry.Result(s): Human corpora lutea in early luteal phase and mid-luteal phase had high VEGF mRNA expression. Expression of VEGF mRNA was significantly reduced in the late luteal phase. Immunohistochemistry showed that VEGF protein was expressed mainly in granulosa lutein cells and faintly in thecal lutein cells. Staining of VEGF protein was decreased in human corpora lutea in the late luteal phase. Expression of Flt-1 and KDR/Flk-1 mRNA was increased in the early luteal phase and mid-luteal phase and decreased in the late luteal phase. Immunohistochemistry showed that Flt-1 and KDR/Flk-1 proteins were expressed mainly in granulosa lutein cells and faintly in thecal lutein cells and endothelial cells in the early luteal phase and mid-luteal phase; their protein staining was reduced in the late luteal phase. Expression of Ets-1 mRNA changed similarly to VEGF and its receptor mRNA in human corpora lutea during the luteal phase.Conclusion(s): Levels of mRNA of VEGF and its receptors Flt-1 and KDR/Flk-1 in human luteal cells may be related to luteal function.

Expression of the ets-1 Proto-Oncogene in Human Colorectal Carcinoma

The proto-oncogene, ets-1, is a transcription factor known to control the expression of a number of genes involved in extracellular matrix remodeling and has been postulated to play a role in cell migration and tumor invasion. To elucidate the involvement of ets-1 in human colorectal carcinomas, we examined 41 cases of colorectal adenoma and 122 cases of colorectal carcinoma by immunohistochemistry and compared the degree of Ets-1 expression with the depth of carcinoma invasion. In adenomas, 12 of 41 cases (29.3%) showed immuno-positivity for Ets-1. 12 of 27 cases (44.4%) of adenoma with high grade dysplasia showed immunopositivity for Ets-1. However, there was no positive case in low or moderate dysplasia of adenoma. In contrast, 103 of 122 cases (84.4%) of colorectal adenocarcinoma showed immunoreactivity for Ets-1 in the carcinoma cells themselves. We investigated the relationship between pathological features in colorectal carcinoma and Ets-1 immunoreactivity of the tumor cells. Among the 122 cases of invasive carcinomas, Ets-1 immunoreactivity was significantly correlated with the depth grading of tumor invasion (P < .0001), the presence of lymph node metastasis (P < .05), lymphatic invasion (P < .01) and venous invasion (P < .05). However, Ets-1 expression did not correlate with histological differentiation. In situ hybridization also confirmed the presence of ets-1 mRNA in colorectal carcinomas. Expression of ets-1 mRNA was also detected in two of three human colorectal carcinoma tissues and in four of six different kinds of carcinoma cell lines by the reverse transcription polymerase chain reaction method. These findings suggest that the expression of Ets-1 is one of the important factors related to carcinogenesis and/or tumor invasion of colorectal carcinoma.

Retinoic Acids Repress the Expression of ETS-1 in Endothelial Cells.

The transcription factor ETS-1 expressed in endothelial cells (ECs) regulates angiogenesis by inducing MMP-1, MMP-3, MMP-9, u-PA and integrin beta3 in endothelial cells (ECs). Here, we examined whether antiangiogenic retinoic acids affect the expression of ETS-1 in ECs. The expression of ets-1 mRNA was up-regulated in sparse to subconfluent ECs and down-regulated in confluent ECs. When confluent ECs were stimulated with basic fibroblast growth factor (bFGF), ets-1 mRNA was induced. All-trans retinoic acid (ATRA) as well as 9-cis retinoic acid reduced the augmented expression of ets-1 mRNA in both subconfluent ECs and bFGF-treated confluent ECs. This inhibitory effect of ATRA was dose dependent and was evident at a concentration as low as 10(-7) M. ATRA did not alter the stability of ets-1 mRNA. Moreover, promoter analysis indicated that ATRA repressed the expression of ets-1 mRNA at transcriptional level. As a result, ATRA reduced the binding of ETS-1 protein to the ETS binding motif. These results indicate that the anti-angiogenic effect of retinoic acids is mediated at least in part by the transcriptional repression of ets-1 mRNA in ECs.

TGF-beta attenuates the transactivation activity of Ets-1 despite its induction via the inhibition of DNA binding.

We examined whether TGF-fl affects the transactivation activity of Ets-1. TGF-beta augmented ets-1 mRNA expression and Ets-1 protein synthesis in ECV304 cells to the level equivalent to bFGF. When the DNA binding activity of Ets-1 protein was examined, bFGF was found to enhance DNA-Ets complex formation, whereas TGF-beta attenuated basal as well as bFGF-enhanced DNA-Ets complex formation. As a result, TGF-beta attenuated the promoter activity driven by Ets-1. The DNA binding of Ets-1 protein was enhanced by the initial 4-hour bFGF treatment and the subsequent 8-hour cycloheximide treatment. When TGF-beta replaced cycloheximide in the subsequent 8-hour treatment, TGF-beta inhibited this bFGF-enhanced DNA-Ets complex formation. When TGF-beta and cycloheximide were simultaneously added in the subsequent 8-hour treatment, the inhibitory effect of TGF-beta on bFGF-enhanced DNA-Ets complex formation was completely abolished. These results suggest the possibility that TGF-beta attenuates the transactivation activity of Ets-1 by inducing a protein that interferes with the binding of Ets-1 to the DNA binding site.

Expression of E1AF/PEA3, an Ets-related transcription factor in human non-small-cell lung cancers: its relevance in cell motility and invasion.

Cell invasion and metastasis characterize the malignant potential of non-small-cell lung cancers (NSCLCs). We have previously reported that E1AF, a member of the Ets-related transcription factor family, confers invasive phenotype on breast cancer and oral squamous-cell carcinoma cell lines. In our study, we analyzed the E1AF expression in cell lines and resected tumors of NSCLCs by Northern blot and in situ hybridization analyses and found that 15 of 17 cell lines and 12 of 19 tumors expressed E1AF mRNA while normal lung tissue and concomitant normal cells within tumors did not. To examine the biologic importance of E1AF in NSCLCs, we introduced the E1AF gene into VMRC-LCD and NCI-H226, NSCLC cell lines lacking E1AF expression, and examined cell motility and invasion activities. E1AF-transfected VMRC-LCD cells showed increased cell motility that was 2-fold that of parental and vector-transfected control cells (p < 0.01), and both cell motility and invasion were increased 1.6-fold in NCI-H226 (p < 0.01). Furthermore, hepatocyte growth factor (HGF), which is one of the most effective cell-scattering factors, stimulated the motile and invasive activities in E1AF-transfected VMRC-LCD and NCI-H226 cells but not in their parental or vector-transfected control cells. Ets-1 mRNA expression was found in E1AF-transfected VMRC-LCD cells but not in parental or vector-transfected cells. HGF further induced expression of the Ets-1 and urokinase-type plasminogen activator (uPA) genes specifically in E1AF-transfected cells. These findings suggest that E1AF plays a substantial role in the cell motility and invasion of NSCLCs.

Renal expression of the Ets-1 proto-oncogene during progression of rat crescentic glomerulonephritis.

The ets-1 proto-oncogene is a member of the transcriptional factor family and was identified by homology to the v-ets oncogene. It was recently demonstrated that Ets-1 protein interacts with the promoter region of the genes coding for proteinases, including matrix metalloproteinase-1 (MMP-1), MMP-3, and urokinase-type plasminogen activator, suggesting that it may play an important role in the regulation of MMP expression. The role of the ets-1 proto-oncogene in advanced glomerular diseases, where extracellular matrix accumulation is observed, remains undefined. In this study, the expression of ets-1 mRNA and protein during the progression of rat crescentic glomerulonephritis was examined using immunohistochemical analysis, reverse transcription-PCR, and in situ hybridization. Passive accelerated anti-glomerular basement membrane-induced nephritis was induced in rats by intravenous injection of nephrotoxic serum. Rats were euthanized on day 7, 14, 21, 28, or 42. Immunohistochemical analysis demonstrated significant upregulation of Ets-1 protein expression in glomeruli and the interstitium in anti-glomerular basement membrane-induced nephritis. The numbers of Ets-1-positive cells were increased 8.8-fold on day 21 in glomeruli (1.2+/-0.1 cells/glomerular cross-section, P<0.001) and sixfold on day 28 in the interstitium (21+/-1.3 cells/mm(2), P<0.001), compared with control samples. Ets-1 protein was predominantly localized in glomerular epithelial cells, endothelial cells, and interstitial cells. A small number of vascular endothelial cells, macrophages, and T cells also expressed Ets-1 protein. MMP-3 deposition was upregulated and positive cells in the interstitium often coexpressed Ets-1, whereas only a few glomerular cells were positive for both MMP-3 and Ets-1 protein. The expression of ets-1 mRNA was also markedly increased in diseased kidneys. The distribution of ets-1 mRNA was similar to that of the protein. These results indicate that overexpression of the ets-1 proto-oncogene by phenotypically altered renal cells might be associated with the pathogenesis of rat crescentic glomerulonephritis.

MRNA Expression of Proto-Oncogenes and Platelet-Derived Growth Factor in Proliferative Vitreoretinal Diseases

Purpose: To detect the expression of mRNA of protooncogenes ets-1, c-jun, c-fos, and platelet-derived growth factor (PDGF) in proliferative membranes of patients with proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). Methods: cDNA was synthesized from mRNA of proliferative membranes from patients with PDR, PVR, premacular fibrosis (PMF), acute retinal necrosis (ARN), and age-related macular degeneration (ARMD). Ets-1, c-jun, c-fos, PDGF-A, and PDGF-B cDNA were amplified using reverse transcriptase-polymerase chain reaction (PCR). Results: Proto-oncogene mRNA was highly expressed in membranes from patients with severe PDR, grade D PVR. PDGF mRNA was expressed in almost all samples. Conclusions: Our results suggest that not only PDGF mRNA was expressed in the membranes of patients with PDR and PVR, but proto-oncogenes ets-1, c-jun, and c-fos mRNA were also expressed.

The Ets1 proto-oncogene is upregulated by retinoic acid: characterization of a functional retinoic acid response element in the Ets1 promoter.

The v-ets oncoprotein and its progenitor Ets1 belong to a family of transcription factors that are related by an 85 amino acid conserved DNA binding domain, the ets domain. Ets1 plays important role(s) in control of cell proliferation, differentiation and apoptosis. Abnormal expression of Ets1 could lead to disruption of these processes and contribute to development of malignancy. Retinoic acid (RA) inhibits proliferation, induces differentiation and regulates apoptosis in many different cell types. Here, we demonstrate that RA treatment increases the expression of Ets1 mRNA, but not that of Ets2, Elk1 or Fli1 in MC3T3-E1 cells. Ets1 induction is detectable after 4 h, can be maintained for at least 14 days, and is inhibited by Actinomycin D, which suggests that RA regulation of Ets1 occurs at the transcriptional level. The promoter region of Ets1 contains four retinoic acid response element (RARE) half sites located at -94, -152, -1765 and -2252 from the translation start site. We show that RARbeta is expressed by MC3T3-E1 cells in the presence of RA and demonstrate that it binds to the -94 RARE half site. Furthermore, RA induces transcription of Ets1 promoter-reporter constructs containing this RARE half site.