1,426 research outputs found
Effect of GnRH analogues on bone-directed metastasis of human breast cancer cells in vitro and in vivo
No full textEffect of GnRH analogues on bone-directed metastasis of human breast cancer cells in vitro and in vivo
No full textAgonists and antagonists of GnRH-I and -II reduce metastasis formation by triple-negative human breast cancer cells in vivo
No full textMetastasis to bone is a frequent problem of advanced breast cancer. Particularly breast cancers, which do not express estrogen and progesterone receptors and which have no overexpression/amplification of the HER2-neu gene, so called triple-negative breast cancers, are considered as very aggressive and possess a bad prognosis. About 60% of all human breast cancers and about 74% of triple-negative breast cancers express receptors for gonadotropin-releasing hormone (GnRH), which might be used as a therapeutic target. Recently, we could show that bone-directed invasion of human breast cancer cells in vitro is time- and dose-dependently reduced by GnRH analogs. In the present study, we have analyzed whether GnRH analogs are able to reduce metastases of triple-negative breast cancers in vivo. In addition, we have evaluated the effects of GnRH analogs on tumor growth. To quantify formation of metastasis by triple-negative MDA-MB-435 and MDA-MB-231 human breast cancers, we used a real-time PCR method based on detection of human-specific alu sequences measuring accurately the amount of human tumor DNA in athymic mouse organs. To analyze tumor growth, the volumes of breast cancer xenotransplants into nude mice were measured. We could demonstrate that GnRH analogs significantly reduced metastasis formation by triple-negative breast cancer in vivo. In addition, we could show that GnRH analogs significantly inhibited the growth of breast cancer into nude mice. Side effects were not detectable. In conclusion, GnRH analogs seem to be suitable drugs for an efficacious therapy for triple-negative, GnRH receptor-positive human breast cancers to prevent metastasis formation.Deutsche Krebshilfe-Dr. Mildred Scheel Stiftung [107224
Data for: Paleoenvironmental and paleoclimatic variations around Lake Van (Eastern Turkey) recorded by sedimentary source specific biomarkers 250- 130 ka (MIS7 and MIS6)
No full textOrganic geochemistry data from a sediment core from Lake Van between 250 and 133ka
Correction to: When terminology hinders research: the colloquialisms of transitions of control in automated driving (Cognition, Technology & Work, (2022), 10.1007/s10111-022-00705-3)
Full text linkIn the original article, author affiliation published with error. The correct affiliations are: Davide Maggi—Institute for Transport Studies, Leeds, UK. Richard Romano—Institute for Transport Studies, Leeds, UK. Oliver Carsten—Institute for Transport Studies, Leeds, UK. Joost C. F. De Winter—Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands. The original article has been corrected.Human-Robot Interactio
Expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand (RANKL) in HCC70 breast cancer cells and effects of treatment with gonadotropin-releasing hormone on RANKL expression
No full textBackground. The majority of human breast cancers and in addition most breast-cancer cell lines express gonadotropin-releasing hormone ( GnRH) receptors. Their proliferation and in addition their bone-directed invasion is time- and dose-dependently reduced by GnRH. Osteolytic metastases are characteristic for breast cancer-derived metastasis. Since the osteolytic activity depends on the receptor activator of nuclear factor-kappa B (NF kappa B) ligand (RANKL)/osteoprotegerin (OPG) ratio, we analyzed RANKL and OPG expression in different breast-cancer cell lines. Methods. Different human breast-cancer cell lines were tested for expression of GnRH receptor, OPG and RANKL. Using a co-culture system of breast-cancer cell lines and human primary osteoblasts (hOB), we analyzed the expression of OPG and RANKL in the GnRH receptor-positive breast-cancer cell line HCC70 co-cultured with or without hOB. In addition, we assessed the effects of GnRH analog treatment on OPG and RANKL mRNA and protein levels. Results. All tested breast-cancer cell lines were GnRH receptor-positive. The majority of these cell lines expressed OPG but not RANKL. The HCC70 breast-cancer cell line derived from an invasive ductal carcinoma with metastases was positive for both OPG and RANKL. The expression of RANKL by HCC70 cells was increased when co-cultured with hOB. Treatment with GnRH analogs reduced the expression of RANKL by HCC70 cells co-cultured with hOB. No effects were observed on breast cancer OPG expression. Conclusions. These data show that the majority of human breast-cancer cell lines express OPG but not RANKL. The HCC70 breast-cancer cell line is RANKL-positive. Co-culture of HCC70 breast cancer cells with hOB increases RANKL expression. Activation of tumor GnRH receptors reduces RANKL expression. These experiments demonstrate that HCC70 breast cancer cells are able to activate osteoclasts directly via RANKL. The interaction between HCC70 breast cancer cells and osteoblasts induces osteoclastogenesis through an increase of RANKL expression. GnRH seems to play an important role by modulating the RANKL expression in HCC70 breast cancer cells
Invasion and increased expression of S100A4 and CYR61 in mesenchymal transformed breast cancer cells is downregulated by GnRH
No full textS100 calcium binding protein A4 (S100A4) and cysteine-rich angiogenic inducer 61 (CYR61) play important roles in epithelial-mesenchymal-transition (EMT), invasion and metastasis by promoting cancer cell motility. Recently we were able to show that invasion of GnRH receptor-positive breast cancer cells is time- and dose-dependently reduced by GnRH analogs. We have now analyzed whether GnRH treatment affects S100A4 and CYR61 in mesenchymal transformed breast cancer cells. S100A4 and CYR61 expression was analyzed using RT-PCR. Invasion was quantified by assessment of breast cancer cell migration rate through an artificial basement membrane. The role of S100A4 and CYR61 in invasion of breast cancer cells was analyzed by neutralizing their biological activity. Expression of S100A4, CYR61 and GnRH receptor in human breast cancers, normal and other non-malignant breast tissues was analyzed by immunohistochemistry. Invasion and expression of S100A4 and CYR61 in MDA-MB-231 breast cancer cells were significant higher as compared with MCF-7 breast cancer cells. Invasion and expression of S100A4 and CYR61 were significantly increased in mesenchymal transformed MCF-7 cells (MCF-7-EMT). The increased invasion of MCF-7-EMT cells could be reduced by anti-S100A4 and anti-CYR61 antibodies. In addition, invasion of MDA-MB-231 cells was decreased by anti-S100A4 and anti-CYR61 antibodies. Treatment of MCF-7-EMT and MDA-MB-231 cells with GnRH agonist Triptorelin resulted in a significant decrease of invasion and expression of S100A4 and CYR61. Both, S100A4 and CYR61 were found highly expressed in biopsy specimens of breast hyperplasia and malignant breast cancers. GnRH receptor expression was detectable in approximately 71% of malignant breast cancers. Our findings suggest that S100A4 and CYR61 play major roles in breast cancer invasion. Both, invasion and expression of S100A4 and CYR61 can be inhibited by GnRH treatment
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