| 1. |
- Eigeliene, Natalija, et al.
(författare)
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Effects of estradiol and medroxyprogesterone acetate on morphology, proliferation and apoptosis of human breast tissue in organ cultures
- 2006
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Human breast tissue undergoes phases of proliferation, differentiation and regression regulated by changes of the levels of circulating sex hormones during the menstrual cycle or aging. Ovarian hormones also likely play a key role in the etiology and biology of breast cancer. Reports concerning the proliferative effects of steroid hormones on the normal epithelium of human breast have been conflicting. Some studies have shown that steroid hormones may predispose breast epithelial cells to malignant changes by stimulating their proliferation, which is known to be regulated tightly by stromal cells. The aim of this study was to investigate the effects of 17 beta-estradiol and medroxyprogesterone acetate on proliferation, apoptosis, expression of differentiation markers and steroid hormone receptors in breast epithelium using an in vitro model of freshly isolated human breast tissue, in which a proper interaction of breast epithelium and stroma has been maintained. Methods: Human breast tissues were obtained from women undergoing surgery for breast tumours. Peritumoral tissues were excised and explants were cultured for 3 weeks in medium supplemented with E-2 or MPA or with E-2+ MPA. Endpoints included histopathological, histomorphometric and immunohistochemical assessment of the breast explants. Results: Culture of breast explants for 14 or 21 days with steroid hormones increased proliferative activity and the thickness of acinar and ductal epithelium. E-2-treatment led to hyperplastic epithelial morphology, MPA to hypersecretory single-layered epithelium and E-2+ MPA to multilayered but organised epithelium. The proliferative response to E-2 in comparison to control ( p < 0.001) was more pronounced than to MPA ( p < 0.05) or E-2+ MPA ( p < 0.05) at 7 and 14 days for Ki-67 and PCNA. E-2 treatment also decreased the proportion of apoptotic cells after 7 ( p < 0.01) and 14 ( p < 0.01) days. In addition, the relative number of ER alpha, ER beta and PR positive epithelial cells was decreased by all hormonal treatments. Conclusion: Organ culture system provides a model for studying the direct effects of steroid hormones and their analogues on postmenopausal human breast tissue.
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| 2. |
- Tuomela, Johanna, et al.
(författare)
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Fast growth associated with aberrant vasculature and hypoxia in fibroblast growth factor 8b (FGF8b) over-expressing PC-3 prostate tumour xenografts
- 2010
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prostate tumours are commonly poorly oxygenated which is associated with tumour progression and development of resistance to chemotherapeutic drugs and radiotherapy. Fibroblast growth factor 8b (FGF8b) is a mitogenic and angiogenic factor, which is expressed at an increased level in human prostate tumours and is associated with a poor prognosis. We studied the effect of FGF8b on tumour oxygenation and growth parameters in xenografts in comparison with vascular endothelial growth factor (VEGF)-expressing xenografts, representing another fast growing and angiogenic tumour model. Methods: Subcutaneous tumours of PC-3 cells transfected with FGF8b, VEGF or empty (mock) vectors were produced and studied for vascularity, cell proliferation, glucose metabolism and oxygenation. Tumours were evaluated by immunohistochemistry (IHC), flow cytometry, use of radiolabelled markers of energy metabolism ([F-18] FDG) and hypoxia ([F-18] EF5), and intratumoral polarographic measurements of pO(2). Results: Both FGF8b and VEGF tumours grew rapidly in nude mice and showed highly vascularised morphology. Perfusion studies, pO(2) measurements, [F-18] EF5 and [F-18] FDG uptake as well as IHC staining for glucose transport protein (GLUT1) and hypoxia inducible factor (HIF) 1 showed that VEGF xenografts were well-perfused and oxygenised, as expected, whereas FGF8b tumours were as hypoxic as mock tumours. These results suggest that FGF8b-induced tumour capillaries are defective. Nevertheless, the growth rate of hypoxic FGF8b tumours was highly increased, as that of well-oxygenised VEGF tumours, when compared with hypoxic mock tumour controls. Conclusion: FGF8b is able to induce fast growth in strongly hypoxic tumour microenvironment whereas VEGF-stimulated growth advantage is associated with improved perfusion and oxygenation of prostate tumour xenografts.
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| 3. |
- Tuomela, Johanna M., et al.
(författare)
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Alendronate decreases orthotopic PC-3 prostate tumor growth and metastasis to prostate-draining lymph nodes in nude mice
- 2008
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Metastatic prostate cancer is associated with a high morbidity and mortality but the spreading mechanisms are still poorly understood. The aminobisphosphonate alendronate, used to reduce bone loss, has also been shown to inhibit the invasion and migration of prostate cancer cells in vitro. We used a modified orthotopic PC-3 nude mouse tumor model of human prostate cancer to study whether alendronate affects prostate tumor growth and metastasis. Methods: PC-3 cells ( 5 x 105) were implanted in the prostates of nude mice and the mice were treated with alendronate ( 0.5 mg/kg/day in PBS, s.c.) or vehicle for 4 weeks. After sacrifice, the sizes of tumor-bearing prostates were measured and the tumors and prostate-draining regional iliac and sacral lymph nodes were excised for studies on markers of proliferation, apoptosis, angiogenesis and lymphangiogenesis, using histomorphometry and immunohistochemistry. Results: Tumor occurrence in the prostate was 73% in the alendronate-treated group and 81% in the control group. Mean tumor size ( 218 mm(3), range: 96-485 mm(3), n = 11) in the alendronate-treated mice was 41% of that in the control mice ( 513 mm(3), range: 209 - 1350 mm(3), n = 13) ( p < 0.05). In the iliac and sacral lymph nodes of alendronate-treated mice, the proportion of metastatic area was only about 10% of that in control mice ( p < 0.001). Immunohistochemical staining of tumor sections showed that alendronate treatment caused a marked decrease in the number of CD34-positive endothelial cells in tumors ( p < 0.001) and an increase in that of ISEL positive apoptotic cells in tumors as well as in lymph node metastases ( p < 0.05) compared with those in the vehicle-treated mice. The density of m-LYVE-I-stained lymphatic capillaries was not changed. Conclusion: Our results demonstrate that alendronate treatment opposes growth of orthotopic PC-3 tumors and decreases tumor metastasis to prostate-draining lymph nodes. This effect could be at least partly explained by decreased angiogenesis and increased apoptosis. The results suggest that bisphosphonates have anti-tumoral and anti-invasive effects on primary prostate cancer.
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| 4. |
- Tuomela, Johanna, et al.
(författare)
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Overexpression of vascular endothelial growth factor C increases growth and alters the metastatic pattern of orthotopic PC-3 prostate tumors
- 2009
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Prostate cancer metastasizes to regional lymph nodes and distant sites but the roles of lymphatic and hematogenous pathways in metastasis are not fully understood. Methods: We studied the roles of VEGF-C and VEGFR3 in prostate cancer metastasis by blocking VEGFR3 using intravenous adenovirus-delivered VEGFR3-Ig fusion protein (VEGFR3-Ig) and by ectopic expression of VEGF-C in PC-3 prostate tumors in nude mice. Results: VEGFR3- Ig decreased the density of lymphatic capillaries in orthotopic PC-3 tumors (p < 0.05) and inhibited metastasis to iliac and sacral lymph nodes. In addition, tumor volumes were smaller in the VEGFR3-Ig-treated group compared with the control group (p < 0.05). Transfection of PC-3 cells with the VEGF-C gene led to a high level of 29/31 kD VEGF-C expression in PC-3 cells. The size of orthotopic and subcutaneous PC-3/VEGF-C tumors was significantly greater than that of PC-3/mock tumors (both p < 0.001). Interestingly, while most orthotopic PC-3 and PC-3/mock tumors grown for 4 weeks metastasized to prostate-draining lymph nodes, orthotopic PC3/VEGF-C tumors primarily metastasized to the lungs. PC-3/VEGF-C tumors showed highly angiogenic morphology with an increased density of blood capillaries compared with PC-3/mock tumors (p < 0.001). Conclusion: The data suggest that even though VEGF-C/VEGFR3 pathway is primarily required for lymphangiogenesis and lymphatic metastasis, an increased level of VEGF-C can also stimulate angiogenesis, which is associated with growth of orthotopic prostate tumors and a switch from a primary pattern of lymph node metastasis to an increased proportion of metastases at distant sites.
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