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EN
Invasion and migration of cancer cells are crucial for the formation of secondary lesions. These require activation of signalling cascades modulated by the number of regulatory molecules. One such molecule is CD151, a member of evolutionary conserved tetraspanin family. CD151 is involved in cell adhesion, motility and cancer progression due to formation of complexes with laminin-binding integrins and regulation of growth factor receptors function (e.g. HGFR, TGFβR, EGFR). Recent studies point to correlation between CD151 expression and high tumour grade in prostate cancer (PCa). Herein, we investigated a possible role of CD151 in communication between PC3 cancer cells and either cancer-associated fibroblasts (CAFs) or osteoblasts, an interplay which is significant for metastasis. The analysis showed that although CAFs strongly enhanced both migration and invasion of PC3 prostate cancer cells, the effect was not dependent on CD151. On the other hand, CD151 was found to promote 3D migration as well as invasive growth in response to osteoblasts-secreted growth factors. Obtained data revealed that knockdown of CD151 abolished activation of pro-migratory/pro-survival kinases (i.e FAK, Src, HSP27) triggered by osteoblasts, along with expression of matrix metalloproteinase-13. This suggests that CD151 participates in communication between PC3 cells and bone microenvironment and the process can be considered as a significant step of PCa progression and metastasis.
EN
Adsorption of human plasma fibrinogen, osteoblasts, and fibroblasts on differently treated titanium samples as implants were examined in this study. Titanium samples were mechanically polished, chemically etched (with and without surface material loss), and grinded. The main goal of this study is to find the best surface treatment of titanium for its possible use as implants. Atomic force microscopy was used to evaluate the adsorption of human plasma fibrinogen onto the titanium samples. Cell counting was used to determine the adherability of osteoblasts and fibroblasts on the titanium samples. Our preliminary results show that the etched titanium surface with surface material loss is the best surface treatment used in our experiments.
EN
Genistein, a major phytoestrogen of soy, is considered a potential drug for prevention and treatment of postmenopausal osteoporosis. The aim of the present study was to compare the effects of genistein, estradiol and raloxifene on the skeletal system in vivo and in vitro. Genistein (5 mg/kg), estradiol (0.1 mg/kg) or raloxifene hydrochloride (5 mg/kg) were administered daily by a stomach tube to mature ovariectomized Wistar rats for 4 weeks. Bone mass, mineral and calcium content, macrometric parameters and mechanical properties were examined. Also the effects of genistein, estradiol and raloxifene (10-9-10-7 M) on the formation of osteoclasts from neonatal mouse bone marrow cells and the activity of osteoblasts isolated from neonatal mouse calvariae were compared. In vivo, estrogen deficiency resulted in the impairment of bone mineralization and bone mechanical properties. Raloxifene but not estradiol or genistein improved bone mineralization. Estradiol fully normalized the bone mechanical properties, whereas genistein augmented the deleterious effect of estrogen-deficiency on bone strength. In vitro, genistein, estradiol and raloxifene inhibited osteoclast formation from mouse bone marrow cells, decreasing the ratio of RANKL mRNA to osteoprotegerin mRNA expression in osteoblasts. Genistein, but not estradiol or raloxifene, decreased the ratio of alkaline phosphatase mRNA to ectonucleotide pyrophosphatase phosphodiesterase 1 mRNA expression in osteoblasts. This difference may explain the lack of genistein effect on bone mineralization observed in ovariectomized rats in the in vivo study. Concluding, our experiments demonstrated profound differences between the activities of genistein, estradiol and raloxifene towards the osseous tissue in experimental conditions.
EN
Bone remodeling is an integrated process of resorption and osteogenesis. Such processes are performed on cyclical basis, as regulated by specifi c bone cells, including osteoclasts, osteoblasts and osteocytes. Not long ago it was claimed that bone remodeling involves only osteoclasts, conditioning bone resorption and osteoblasts, responsible for osteogenesis. Recent studies have shown however, that the major regulatory part in bone remodeling is taken by osteocytes. Such cells regulate the activity of osteoclasts and osteoblasts, infl uencing the RANK/RANKL/OPG pathway as well as the signalling canonical pathway Wint/􀈕-catenine. The role of osteocytes in regulation of RANK/RANKL/OPG pathway is basically associated with regulation of RANKL secretion by osteoblasts, while in regulation of Wnt/ /􀈕-catenine, with secretion of sclerostin, which inhibits osteogenesis by blocking activation, proliferation and diff erentiation of osteoblasts from the mesenchymal stem cells and slows down Wnt/􀈕-catenine signalling.
PL
Aktywność metaboliczna szkieletu związana jest z ciągłą przebudową tkanki kostnej. Mechanizm ten jest niezbędny do przystosowania szkieletu do warunków zewnętrznych i obciążeń mechanicznych oraz zapewnia równowagę mineralną. Prawidłowy przebieg procesu przebudowy kości zależy od aktywności komórek kostnych, do których należą osteoblasty, osteoklasty i osteocyty. Osteoblasty uczestniczą w kościotworzeniu oraz resorpcji kości. Wydzielają cytokiny i czynniki wzrostu, dzięki czemu pełnią rolę regulacyjną procesu osteoklastogenezy i resorpcji kości przez wpływ na szlak regulacyjny RANK/RANKL/OPG. Osteocyty z kolei regulują osteoblastogenezę, proces apoptozy osteoblastów oraz funkcję szlaku RANK/RANKL/OPG przez wpływ na kanoniczny szlak sygnalizacyjny Wnt/􀈕-katenina. Osteocyty wydzielają również sklerostynę, działającą antagonistycznie w stosunku do szlaku kanonicznego WNT/􀈕–katenina. Sklerostyna hamuje proces kościotworzenia. Szlak Wnt/􀈕–katenina może być potencjalnym celem terapii, prowadzącym do zwiększenia masy kostnej, natomiast sklerostyna – jako inhibitor tego szlaku – stanowi nowy obiecujący cel w badaniach nad terapią anaboliczną schorzeń tkanki kostnej.
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