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ABSTRACT: Tumstatin is a candidate tumor suppressor that plays an important role in tumor growth and angiogenesis. The purpose of this study was to evaluate the correlation between tumstatin-mRNA expression and the clinicopathologic characteristics, tumor angiogenesis, outcome of patients with non-small cell lung cancer (NSCLC). Specimens from 68 patients with NSCLC were recruited in this study. Tumstatin-mRNA expression and protein level in tumor tissues were quantified respectively by quantitative RT-PCR and ELISA. Microvessel density (MVD) was determined by CD34 immunostaining. The correlation of tumstatin-mRNA expression levels with clinicopathologic variables, tumor angiogenesis, and prognosis was analyzed. Tumstatin-mRNA expression levels were decreased in tumor. Tumstatin-mRNA expression level was significantly correlated with its protein level in tumor (r = 0.562; P = 0.001). Tumstatin-mRNA expression levels in poorly differentiated tumor tissues were significantly lower than in well-differentiated tumor tissues (P < 0.004). Furthermore, tumor tumstatin-mRNA expression were also significantly related to tumor pathologic stage (P = 0.032) and MVD (r = -0.77, P < 0.0001). Overall survival (OS) and disease-free survival (DFS) analysis indicated that NSCLC patients with low tumstatin-mRNA expression had poorer OS and DFS than those with high expression (P = 0.015 and 0.037; respectively). Multivariable Cox regression analysis revealed that the tumstatin-mRNA expression could be an independent prognostic indicators in both DFS and OS. Tumstatin-mRNA expression levels are down-regulated in NSCLC tissues. Tumstatin-mRNA expression level correlates with prognosis, which suggests that tumstatin-mRNA is a new potential independent marker of favorable prognosis in NSCLC.
International Union of Biochemistry and Molecular Biology Life 05/2012; 64(5):423-31. · 3.51 Impact Factor
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ABSTRACT: Tumstatin, an angiogenesis inhibitor with anti-tumor activity in mice, is the bioactive NC1 domain of Col IVa3, the potential significance of tumstatin as an endogenous angiogenesis inhibitor in human is not yet completely understood. This study aimed to develop an enzyme-linked immunoassay (ELISA) for tumstatin to accurately measure its concentrations in biological samples.
Recombinant tumstatin as an immunogen was expressed by E.coli. The purified tumstatin was injected into mice for antibody generation. An ELISA was developed with the monoclonal antibodies.
The detection limit of the ELISA was 1.4ng/ml, and the intra- and inter- assay CVs were within 10%. Recovery of tumstatin added to sera was 92.7-115%. Patients with metastases had serum tumstatin levels 50% lower than patients without metastases (P=0.039). Tumstatin levels in poorly differentiated tumor tissues were significantly lower than in nontumorous tissues and well-differentiated tumor tissues (P<0.001).
The development of a highly sensitive and reliable ELISA method capable of quantifying tumstatin in human serum samples and tissue extracts is reported. This assay for tumstatin in biological samples may be helpful in evaluating the therapeutic and/or prognostic value of tumstatin in cancer patients.
Clinica chimica acta; international journal of clinical chemistry 04/2010; 411(7-8):510-5. · 2.54 Impact Factor
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ABSTRACT: Tumstatin, a 28-kDa C-terminal fragment of collagen IV, is a potent anti-angiogenic protein and inhibitor of tumour growth. Recombinant tumstatin was prepared from Escherichia coli deposited as insoluble, inactive inclusion bodies. In the present study, we produced soluble and biologically active recombinant human tumstatin in E. coli by the coding region of tumstatin being linked to the 3'-end of the maltose-binding protein (MBP) gene. The fusion protein was expressed as the soluble form after induction by isopropylthio-beta-D-galactoside (IPTG). MBP-tumstatin was purified by amylose affinity chromatography. MBP can be removed by digestion with factor Xa. Expression could represent 20% of the total soluble protein in E. coli, allowing approximately 8.6 mg of highly purified protein to be obtained per litre of bacterial culture. The purified tumstatin specifically inhibited the proliferation of endothelial cells in a dose-dependent manner. Annexin V-FITC apoptotic assay showed that recombinant tumstatin induced significant increase of apoptotic endothelial cells after 20 h of exposure to 20 microg/ml tumstatin, and when tumstatin was incubated on the chicken embryo, chorioallantoic membrane at doses of 1-15 microg, there was a dramatic decrease in the microvasculature allantoids of chicken embryos neovascular vessel test in vivo demonstrated that tumstatin treatment at doses of 1-15 microg gives rise to dramatically decrease the number of neovascular vessel. Our study provides a feasible and convenient approach to produce soluble and biologically active tumstatin.
Clinical and Experimental Medicine 04/2008; 8(1):37-42. · 1.58 Impact Factor
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ABSTRACT: The anti-angiogenic activity of tumstatin45-132 is mediated by binding to alphaVbeta3 on endothelial cells and tumor vascular endothelium showing increased expression of alphaVbeta3. Tumor necrosis factor alpha (TNF-alpha) is known to not only possess direct cytotoxicity against tumor cells, but also induces tumor vessel disruption, however, clinical use of TNF-alpha as an anticancer drug is hampered by severe systemic toxicity. In this study, we explore the possibility of fusing tumstatin45-132 with human TNF-alpha in the hope of generating a targeting, bi-functional protein in tumor treatment. Tumstatin45-132-TNF was constructed and expressed in E. coli. The recombinant fusion protein was shown to be insoluble and in an inclusion body form. An effective strategy for refolding and purification of tumstatin45-132-TNF resulted in final purified yields of 3 mg purified fusion protein recovered from 1 liter of E. coli culture. The refolded tumstatin45-132-TNF with a purity of 98% assessed by denaturing SDS - PAGE showed a single band on gels. Endothelial cell proliferation assay and standard cytolytic assays against L929 indicated that the fusion protein maintains tumstatin45-132 and TNF-alpha activity. More importantly, tumstatin45-132-TNF inhibits endothelial cell proliferation more than tumstatin45-132 alone. Cell adhesion assays and competitive binding experiments with anti-integrin antibodies showed that the tumstatin45-132 moiety specifically interacts with alphaVbeta3 integrin. These results lay the solid foundation for further investigation of antitumor activity of tumstatin45-132-TNF in vivo.
International Union of Biochemistry and Molecular Biology Life 12/2006; 58(11):647-53. · 3.51 Impact Factor
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ABSTRACT: This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
Journal of Hepatology 10/2005; · 9.26 Impact Factor
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ABSTRACT: To clone tumstatin(45-132) gene and to express recombinant human tumstatin(45-132) in E. coli BL21.
Tumstatin gene was cloned by RT-PCR and then tumstatin(45-132) gene amplified from tumstatin gene was cloned into pBV220. The recombinant plasmid pBV220-tumstatin(45-132) was sequenced and transformed into E.coli BL21. E. coli BL21 transformed with the recombinant plasmid pBV220-tumstatin(45-132) was induced at 42 degrees Celsius. After the recombinant tumstatin(45-132) was purified, its bioactivity was detected by endothelia cell proliferation test.
264 bp tumstatin(45-132) fragment was cloned and its sequence was identical with that in GenBank. The tumstatin(45-132) was expressed in E. coli BL21. Expressed product accounted for about 10% of total bacterial proteins and its relative molecular mass (M(r)) was 9,600. The purified protein showed inhibitory effect on proliferation of endothelia cells ECV304 in vitro.
tumstatin(45-132) gene has been cloned and expressed successfully in E.coli BL21. Expressed tumstatin(45-132) can inhibit the proliferation of endothelial cell ECV304.
Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 04/2005; 21(2):141-3.
