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Mengxian Zhang,
Susanne Kleber,
Manuel Röhrich,
Carmen Timke, Na Han,
Jochen Tuettenberg,
Ana Martin-Villalba,
Juergen Debus,
Peter Peschke,
Ute Wirkner,
Michael Lahn,
Peter E Huber
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ABSTRACT: Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor that tends to be resistant to the ionizing radiotherapy used to treat it. Because TGF-β is a modifier of radiation responses, we conducted a preclinical study of the antitumor effects of the TGF-β receptor (TGFβR) I kinase inhibitor LY2109761 in combination with radiotherapy. LY2109761 reduced clonogenicity and increased radiosensitivity in GBM cell lines and cancer stem-like cells, augmenting the tumor growth delay produced by fractionated radiotherapy in a supra-additive manner in vivo. In an orthotopic intracranial model, LY2109761 significantly reduced tumor growth, prolonged survival, and extended the prolongation of survival induced by radiation treatment. Histologic analyses showed that LY2109761 inhibited tumor invasion promoted by radiation, reduced tumor microvessel density, and attenuated mesenchymal transition. Microarray-based gene expression analysis revealed signaling effects of the combinatorial treatments that supported an interpretation of their basis. Together, these results show that a selective inhibitor of the TGFβR-I kinase can potentiate radiation responses in glioblastoma by coordinately increasing apoptosis and cancer stem-like cells targeting while blocking DNA damage repair, invasion, mesenchymal transition, and angiogenesis. Our findings offer a sound rationale for positioning TGFβR kinase inhibitors as radiosensitizers to improve the treatment of glioblastoma.
Cancer Research 12/2011; 71(23):7155-67. · 7.86 Impact Factor
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ABSTRACT: Here we investigate the effects of the novel transforming growth factor-β receptor I (TGF-βRI) serine/threonine kinase inhibitor LY2109761 on glioblastoma when combined with the present clinical standard combination regimen radiotherapy and temozolomide (TMZ). Human GBM U87 (methylated MGMT promoter), T98 (unmethylated MGMT promoter), and endothelial cells (HUVECs) were treated with combinations of LY2109761, TMZ, and radiation. We found that LY2109761 reduced clonogenic survival of U87 and T98 cells and further enhanced the radiation-induced anticlonogenicity. In addition, LY2109761 had antimigratory and antiangiogenic effects in Matrigel migration and tube formation assays. In vivo, in human xenograft tumors growing subcutaneously on BALB/c nu/nu mice, LY2109761 delayed tumor growth alone and in combination with fractionated radiation and TMZ. Interestingly, as expected, the methylated U87 model was more sensitive to TMZ than the unmethylated T98 model in all experiments, whereas the opposite was found for LY2109761. Moreover, with respect to tumor angiogenesis, while LY2109761 decreased the glioblastoma proliferation index (Ki-67) and the microvessel density (CD31 count), the relative pericyte coverage (α-SMA/CD31 ratio) increased in particular after triple therapy, suggesting a vascular normalization effect induced by LY2109761. This normalization could be attributed in part to a decrease in the Ang-2/Ang-1 messenger RNA ratio. LY2109761 also reduced tumor blood perfusion as quantified by noninvasive dynamic contrast-enhanced magnetic resonance imaging. Together, the data indicate that the addition of a TGF-βRI kinase inhibitor to the present clinical standard (radiation plus TMZ) has the potential to improve clinical outcome in human glioblastoma, especially in patients with unmethylated MGMT promoter status.
Neoplasia (New York, N.Y.) 06/2011; 13(6):537-49. · 5.48 Impact Factor
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ABSTRACT: To construct a CXCR4 specific recombinant plasmid vector and study its inhibiting effect on invasion capacity in vitro of human breast cancer MDA-MB-231 cell line and its metastatic potential to the lung in nude mice.
A CXCR4 specific recombinant plasmid vector was constructed and transfected into the cultured MDA-MB-231 cell line with lipofectamine 2000. RT-PCR and Western blot were used to detect the mRNA and protein expression of CXCR4, respectively. Invasion capability in vitro of the cells was evaluated by Boyden chamber. The cell proliferation capacity was detected by MTT method. The nude mouse model of lung metastasis was established by injection of MDA-MB-231 cells into the tail vein. The animals were sacrificed at 6 weeks after the tumor cells injection. Whole lung tissues were harvested, embedded in paraffin, sectioned serially, and the HE-stained paraffin sections were examined pathologically to evaluate the presence and number of metastatic tumors.
The CXCR4 mRNA expression rate was 29.5% +/- 3.8% in the CXCR4-shRNA group, significantly lower than that of the control group (69.7% +/- 2.6%, P < 0.01) and mock-control group (67.8% +/- 3.5%, P < 0.01). The CXCR4 protein expression rate was 15.4% +/- 1.1% in the CXCR4-shRNA group, significantly lower than that of the control group (39.0% +/- 2.4%, P < 0.01) and mock-control group (35.9% +/- 3.9%, P < 0.01). Silencing of CXCR4 by shRNA lead to a significant decrease in breast cancer cell invasion and proliferation capacity in vitro. Furthermore, tumor cells with CXCR4 shRNA permanent transfcetion had a much lower lung metastatic potential in nude mice than control cells and mock control cells in vivo.
CXCR4 shRNA can inhibit the expression of CXCR4 and decrease the invasion and lung metastatic potential of human breast cancer cells.
Zhonghua zhong liu za zhi [Chinese journal of oncology] 05/2008; 30(5):325-9.
