The effects of aging on tumor growth and angiogenesis are tumor-cell dependent
ABSTRACT It is generally accepted that histologically similar tumors grow more slowly, with less angiogenesis, in aged mice relative to young mice. We subcutaneously implanted TRAMP-C2 tumor cells, a prostate cancer cell line not previously examined in aging, into syngeneic C57/Bl6 young (4 month) and aged (20 month) mice and compared tumor growth and angiogenesis. Unexpectedly, the prostate tumors grew as fast in aged as in young mice. Angiogenesis in TRAMP-C2 tumors was robust, with no differences between the young and aged mice in the number of vessels, distribution of vessel sizes or features of vessel maturation. Aged mice had lower levels of serum testosterone than the young mice. VEGF levels were similar in the tumors and sera of the young and aged mice. Comparison with B16/F10 melanoma, a cancer cell line that is representative of previous studies in aged mice, showed that B16/F10 tumors grew minimally in the aged mice. In contrast to the B16/F10, TRAMP-C2 tumors had an extracellular matrix with significantly higher levels of MMP2 and MMP9 expression and activity. These unique results demonstrate that tumor progression can be as robust in aged tissues as young tissues. The ability of aged mice to grow large, vascularized prostate tumors is associated with high levels of MMP2/9 activity that may produce a permissive environment for tumor growth and angiogenesis. These data demonstrate that tumor-cell specific features determine the effect of aging on tumor growth and angiogenesis.
- SourceAvailable from: Larissa Akemi Kido[Show abstract] [Hide abstract]
ABSTRACT: The aim of this study was to evaluate the structural and molecular effects of antiangiogenic therapies and finasteride on the ventral prostate of senile mice. 90 male FVB mice were divided into: Young (18weeks old) and Senile (52weeks old) groups; Finasteride group: Finasteride (20mg/kg); SU5416 group: SU5416 (6mg/kg); TNP-470 group: TNP-470 (15mg/kg,) and SU5416+TNP-470 group: similar to the SU5416 and TNP-470 groups. After 21days, prostate ventral lobes were collected for morphological, immunohistochemical and Western Blotting analyses. The results demonstrated atrophy, occasional proliferative lesions and inflammatory cells in the prostate during senescence, which were interrupted and/or blocked by treatment with antiangiogenic drugs and finasteride. Decreased AR and Endostatin reactivities, and an increase for ER-α, ER-β and VEGF were seen in the senile group. Decreased VEGF and ER-α reactivities and increased ER-β reactivity were verified in the finasteride, SU5416 groups and especially in SU5416+TNP-470 group. The TNP-470 group showed reduced AR and ER-β protein levels. The senescence favored the occurrence of structural and/or molecular alterations suggesting the onset of malignant lesions, due to the imbalance in the signaling between the epithelium and stroma. The SU5416+TNP-470 treatment was more effective in maintaining the structural, hormonal and angiogenic factor balance in the prostate during senescence, highlighting the signaling of antiproliferation via ER-β.Life sciences 05/2014; DOI:10.1016/j.lfs.2014.04.027 · 2.30 Impact Factor
Article: Aging and cancer cell biology, 2007[Show abstract] [Hide abstract]
ABSTRACT: This Hot Topics review, the second in a new Aging Cell series, discusses articles published in the last year that have stimulated new ideas about the tangled relationship of aging to cancer cell biology. The year's highlights include reports on the ability of Mdm2 mutations to diminish risks of cancer in aging mice, on proliferative competition between oncogenic cells and bone marrow stem cells, and on the role of metalloproteinases in overcoming age-associated barriers to tumor invasion. Of particular interest were three articles showing that diminished activity of the tumor-suppressor gene p16/INK4a, while increasing the risk of cancer mortality, can lead to improved function in several varieties of age-sensitive stem cells.Aging Cell 07/2007; 6(3):261-3. DOI:10.1111/j.1474-9726.2007.00292.x · 5.94 Impact Factor
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ABSTRACT: Electroforming processes such as electroplating was used in conjunction with photoresist mold to fabricate surface and substrate micromachined structure. Gold, gold alloys and nickel and nickel-iron alloys were used as structural material in this technique. In case of surface micromachining free standing, cantilevers, bridges and linear and torsional comb drives on silicon substrate were fabricated, whereas in case of substrate micromachined magnetic actuators were fabricated using the above mentioned technology. The thickness of metallic microstructures varied from 8 μm to 20 μm. This presentation discusses the technology we have developed in our laboratory to fabricate affordable metallic microstructures, as well as presenting functional devices we have built to demonstrate the potential of this technologyElectrical and Computer Engineering, 1996. Canadian Conference on; 06/1996