Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line

[Background] Despite significant advancement in breast cancer therapy, there is a great need for a better understanding of the mechanisms involved in breast carcinogenesis and progression, as well as of the role of epigenetic contributions from stromal cells in mammary tumorigenesis. In this study, we isolated and characterized murine mammary tumor-derived epithelial and myofibroblast cell lines, and investigated the in vitro and in vivo effect of cellular soluble factors produced by the epithelial cell line on tumor cells[Methods] Morphology, immunophenotype, cytogenetics, invasiveness, and tumorigenicity of epithelial (LM-234ep) and myofibroblast (LM-234mf) cell lines isolated from two murine mammary adenocarcinomas with common ancestor were studied. The in vitro effects of LM-234ep conditioned medium on proliferation, cell cycle distribution, and expression of cell cycle proteins, were investigated in LM-234mf cells, mouse melanoma cells (B16-F10), and human cervical adenocarcinoma cells (HeLa). The in vivo anti-tumor activity of LM-234ep conditioned media was evaluated in subcutaneous tumors formed in nude mice by B16-F10 and HeLa cells.[Results] LM-234ep cells were found to be cytokeratin positive and hipertriploid, whereas LM- 234mf cells were α-smooth muscle actin positive and hypohexaploid. Chromosome aberrations were found in both cases. Only LM-234mf revealed to be invasive in vitro and to secrete active MMP-2, though neither of the cell types were able to produce progressing tumors. LM-234epderived factors were able to inhibit the in vitro growth of LM-234mf, B16-F10, and HeLa cells, inducing cell cycle arrest in G0/G1 phase. The administration of LM-234ep conditioned medium inhibited the growth of B16-F10 and HeLa tumors in nude mice.[Conclusion] Our data suggest the existence of epithelial cell variants with tumor suppressive properties within mammary tumors. To our knowledge, this is the first report showing antiproliferative and antineoplastic activities induced by tumor-derived epithelial cells.This work was supported by Cancer Research Foundation (Fundación de Investigación del Cáncer, FUNDIC), Buenos Aires, Argentina.Peer reviewe

Immunotherapies for Neurodegenerative Diseases

The current treatments for neurodegenerative diseases are mostly symptomatic without affecting the underlying cause of disease. Emerging evidence supports a potential role for immunotherapy in the management of disease progression. Numerous reports raise the exciting prospect that either the immune system or its derivative components could be harnessed to fight the misfolded and aggregated proteins that accumulate in several neurodegenerative diseases. Passive and active vaccinations using monoclonal antibodies and specific antigens that induce adaptive immune responses are currently under evaluation for their potential use in the development of immunotherapies. In this review, we aim to shed light on prominent immunotherapeutic strategies being developed to fight neuroinflammation-induced neurodegeneration, with a focus on innovative immunotherapies such as vaccination therapy

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line

<p>Abstract</p> <p>Background</p> <p>Despite significant advancement in breast cancer therapy, there is a great need for a better understanding of the mechanisms involved in breast carcinogenesis and progression, as well as of the role of epigenetic contributions from stromal cells in mammary tumorigenesis. In this study, we isolated and characterized murine mammary tumor-derived epithelial and myofibroblast cell lines, and investigated the <it>in vitro </it>and <it>in vivo </it>effect of cellular soluble factors produced by the epithelial cell line on tumor cells.</p> <p>Methods</p> <p>Morphology, immunophenotype, cytogenetics, invasiveness, and tumorigenicity of epithelial (LM-234ep) and myofibroblast (LM-234mf) cell lines isolated from two murine mammary adenocarcinomas with common ancestor were studied. The <it>in vitro </it>effects of LM-234ep conditioned medium on proliferation, cell cycle distribution, and expression of cell cycle proteins, were investigated in LM-234mf cells, mouse melanoma cells (B16-F10), and human cervical adenocarcinoma cells (HeLa). The <it>in vivo </it>anti-tumor activity of LM-234ep conditioned media was evaluated in subcutaneous tumors formed in <it>nude </it>mice by B16-F10 and HeLa cells.</p> <p>Results</p> <p>LM-234ep cells were found to be cytokeratin positive and hipertriploid, whereas LM-234mf cells were α-smooth muscle actin positive and hypohexaploid. Chromosome aberrations were found in both cases. Only LM-234mf revealed to be invasive <it>in vitro </it>and to secrete active MMP-2, though neither of the cell types were able to produce progressing tumors. LM-234ep-derived factors were able to inhibit the <it>in vitro </it>growth of LM-234mf, B16-F10, and HeLa cells, inducing cell cycle arrest in G₀/G₁phase. The administration of LM-234ep conditioned medium inhibited the growth of B16-F10 and HeLa tumors in <it>nude </it>mice.</p> <p>Conclusion</p> <p>Our data suggest the existence of epithelial cell variants with tumor suppressive properties within mammary tumors. To our knowledge, this is the first report showing antiproliferative and antineoplastic activities induced by tumor-derived epithelial cells.</p

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line

Background Despite significant advancement in breast cancer therapy, there is a great need for a better understanding of the mechanisms involved in breast carcinogenesis and progression, as well as of the role of epigenetic contributions from stromal cells in mammary tumorigenesis. In this study, we isolated and characterized murine mammary tumor-derived epithelial and myofibroblast cell lines, and investigated the in vitro and in vivo effect of cellular soluble factors produced by the epithelial cell line on tumor cells. Methods Morphology, immunophenotype, cytogenetics, invasiveness, and tumorigenicity of epithelial (LM-234ep) and myofibroblast (LM-234mf) cell lines isolated from two murine mammary adenocarcinomas with common ancestor were studied. The in vitro effects of LM-234ep conditioned medium on proliferation, cell cycle distribution, and expression of cell cycle proteins, were investigated in LM-234mf cells, mouse melanoma cells (B16-F10), and human cervical adenocarcinoma cells (HeLa). The in vivo anti-tumor activity of LM-234ep conditioned media was evaluated in subcutaneous tumors formed in nude mice by B16-F10 and HeLa cells. Results LM-234ep cells were found to be cytokeratin positive and hipertriploid, whereas LM-234mf cells were α-smooth muscle actin positive and hypohexaploid. Chromosome aberrations were found in both cases. Only LM-234mf revealed to be invasive in vitro and to secrete active MMP-2, though neither of the cell types were able to produce progressing tumors. LM-234ep-derived factors were able to inhibit the in vitro growth of LM-234mf, B16-F10, and HeLa cells, inducing cell cycle arrest in G0/G1 phase. The administration of LM-234ep conditioned medium inhibited the growth of B16-F10 and HeLa tumors in nude mice. Conclusion Our data suggest the existence of epithelial cell variants with tumor suppressive properties within mammary tumors. To our knowledge, this is the first report showing antiproliferative and antineoplastic activities induced by tumor-derived epithelial cells

Prostate Cancer Cell-Derived Urokinase-Type Plasminogen Activator Contributes to Intraosseous Tumor Growth and Bone Turnover1

A variety of proteases have been implicated in prostate cancer (PC) bone metastasis, but the individual contributions of these enzymes remain unclear. Urokinase-type plasminogen activator (uPA), a serine protease, can activate plasminogen and stimulate signaling events on binding its receptor uPAR. In the present study, we investigated the functional role of PC cell-associated uPA in intraosseous tumor growth and bone matrix degradation. Using a severe combined immunodeficient-human mouse model, we found that PC3 cells were the major source of uPA in the experimental bone tumor. Injection of uPA-silenced PC3 cells in bone xenografts resulted in significant reduction of bone tumor burdens and protection of trabecular bones from destruction. The suppressed tumor growth was associated with the level of uPA expression but not with its activity. An increase in the expression of PAI-1, the endogenous uPA inhibitor, was found during in vitro tumor-stromal interactions. Up-regulation of PAI-1 in bone stromal cells and preosteoclasts/osteoblasts was due to soluble factor(s) released by PC cells, and the enhanced PAI-1 expression in turn stimulated PC cell migration. Our results indicate that both tumor-derived uPA and tumor-stroma-induced PAI-1 play important roles in intraosseous metastatic PC growth through regulation of a uPA-uPAR-PAI-1 axis by autocrine/paracrine mechanisms

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line-8

<p><b>Copyright information:</b></p><p>Taken from "Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line"</p><p>http://www.biomedcentral.com/1471-2407/7/184</p><p>BMC Cancer 2007;7():184-184.</p><p>Published online 1 Oct 2007</p><p>PMCID:PMC2129098.</p><p></p>C-conjugated primary antibody. Nuclei (blue staining) were identified using DAPI. Cytokeratin was undetectable in LM-234mf (B), whereas strongly expressed in LM-234ep (D), as revealed by immunohistochemistry using an anti-Pan cytokeratin antibody. Magnification bar, 100 μm. Cell lysates (25 μg/lane) were analyzed using Western blot for cytokeratins (E) and αSMA (F). The cytokeratins detected with the anti-pan antibody used range between 40 and 68 kDa. The band immunodetected for αSMA has an approximate molecular weight of 42 kDa. Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH) was used as a loading control

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line-5

<p><b>Copyright information:</b></p><p>Taken from "Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line"</p><p>http://www.biomedcentral.com/1471-2407/7/184</p><p>BMC Cancer 2007;7():184-184.</p><p>Published online 1 Oct 2007</p><p>PMCID:PMC2129098.</p><p></p>× 10cells/well and allowed to attach overnight. Cells were incubated with LM-234ep CM (black circles), LM-234mf CM (black triangles), or culture medium (black squares) containing 10% FBS (Control), and counted at different time points. Data are shown as mean ± SE. * = 0.05, ** = 0.0018, *** = 0.0006, **** < 0.0001 (Student's t Test). Assays were performed in triplicate

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line-4

<p><b>Copyright information:</b></p><p>Taken from "Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line"</p><p>http://www.biomedcentral.com/1471-2407/7/184</p><p>BMC Cancer 2007;7():184-184.</p><p>Published online 1 Oct 2007</p><p>PMCID:PMC2129098.</p><p></p> and allowed to attach overnight. Thereafter, cells were incubated in the presence of LM-234ep CM (black circles), LM-234mf CM (black triangles), or culture medium (black squares) supplemented with 10% FBS. Cell numbers were counted at different time points, and expressed as mean ± SE. * = 0.05, ** = 0.0018 (Student's t Test). Assays were performed in triplicate, (A). LM-234mf cells were incubated with culture medium + 10% FBS (Control) or LM-234ep CM for 72 h. Cells were processed for DNA content, and cell cycle progression was analyzed by flow cytometry (B). LM-234mf cells were treated with culture medium (Control) or LM-234ep CM for the times indicated (top). Cells were collected, lysed, and analyzed by immunoblotting using antibodies specific for p-ERK, c-Jun, JunB, cyclins E, A, and D, and Cdk2. β-actin was used as a loading control (C). Immunofluorescence for c-Jun, Cyclin A and Cyclin D in LM-234mf cells. The nuclear localization of the proteins is shown in the control cells (white arrows). Magnification bar, 40 μm (D). AP-1 luciferase activity in LM-234mf cells co-transfected with AP-1-Luc and pRL-tk-luc and treated with LM-234ep CM or culture medium (Control). ** = 0.005 (Student's t Test). The results shown are the mean ± S.D. of three experiments (E)

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line-1

<p><b>Copyright information:</b></p><p>Taken from "Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line"</p><p>http://www.biomedcentral.com/1471-2407/7/184</p><p>BMC Cancer 2007;7():184-184.</p><p>Published online 1 Oct 2007</p><p>PMCID:PMC2129098.</p><p></p>. A minimum of 50 metaphase spreads was analyzed in each case. Representative metaphases of LM-234ep (C) and LM-234mf (D) cells. Arrows point different chromosomal aberrations including: acentric fragments (1), chromosome break (2), and centromeric fusion (3). Magnification, × 1000

Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line-0

<p><b>Copyright information:</b></p><p>Taken from "Paradoxical antiproliferative effect by a murine mammary tumor-derived epithelial cell line"</p><p>http://www.biomedcentral.com/1471-2407/7/184</p><p>BMC Cancer 2007;7():184-184.</p><p>Published online 1 Oct 2007</p><p>PMCID:PMC2129098.</p><p></p>C-conjugated primary antibody. Nuclei (blue staining) were identified using DAPI. Cytokeratin was undetectable in LM-234mf (B), whereas strongly expressed in LM-234ep (D), as revealed by immunohistochemistry using an anti-Pan cytokeratin antibody. Magnification bar, 100 μm. Cell lysates (25 μg/lane) were analyzed using Western blot for cytokeratins (E) and αSMA (F). The cytokeratins detected with the anti-pan antibody used range between 40 and 68 kDa. The band immunodetected for αSMA has an approximate molecular weight of 42 kDa. Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH) was used as a loading control