a1_Proteinase-activated receptor-2 (PAR-2) is a ubiquitous surface molecule participating in many biological processes. It belongs to the family of G protein-coupled receptors activated by the site-specific proteolysis of trypsin and similar proteases. Altered function of PAR-2 has been described in different malignant tumors. In the present study, we investigated the expression of PAR-2 in breast cancer surgical specimens and the role of trypsin in breast cancer cell line MDA MB-231 proliferation and metabolism. A total of 40 surgical samples of infiltrative ductal breast cancer and breast cancer cell line were included in this study. We analyzed PAR-2 expression by immunohistochemistry, RT-PCR and western blot. Activation of PAR-2 on cell line MDA MB-231 was measured using calcium mobilization assay determined by flow cytometry. MTT cell metabolism assay and cell count analysis were used to assess the trypsin influence on breast cancer cell line MDA MB-231 proliferation. Immunohistochemical examination showed the expression of PAR-2 in all samples of breast cancer surgical specimens and high levels of cell lines which was confirmed by RT-PCR and western blot., a2_Calcium mobilization assay corroborated the activation of PAR-2 on cell line MDA MB-231 either by trypsin or by an agonistic peptide. Cell metabolism assay and cell count analysis showed significant differences of proliferative activity of breast cancer cells dependent on the presence or absence of trypsin and serum in the culture medium. PAR-2 is expressed by high levels in infiltrative ductal breast cancer tissue specimens. PAR-2 is also strongly expressed in studied breast cancer cell lines. PAR-2 is activated by trypsin and also by agonistic peptide in the model of breast cancer cell line MDA MB-231. Activation of PAR-2 in vitro influences proliferative and metabolic activity of breast cancer cell line MDA MB-231. The action of trypsin is modified by the presence of serum which is a potential source of protease inhibitors., R. Matěj, P. Manďáková, I. Netíková, P. Poučková, T. Olejár., and Obsahuje biblografii a bibliografické odkazy
Lipokaliny tvoří velkou skupinu malých extracelulárních proteinů. Vykazují velkou rozmanitost na úrovni sekvenčního uspořádání, terciární struktura je oproti tomu vysoce konzervovaná a představuje ji β-válec tvořený osmi antiparalelními strukturami β-skládaného listu. Vazebné místo ligandu se nachází uvnitř β-válce. Zastávají rozličné funkce, např. transportují retinoidy, steroidy, biliny, feromony, účastní se syntézy prostaglandinů, tvorby ochranného zbarvení bezobratlých, vytváření čichových vjemů, jsou zapojené do regulace buněčné homeostázy a modulace imunitní odpovědi. Lipokalin-2 (neutrofilní s gelatinázou asociovaný lipokalin), časný marker různých typů renálního poškození, vykazuje pleiotropní biologické aktivity v různých typech buněk a tkání. Hraje významnou roli v angiogenezi, apoptóze, organogenezi, zánětu, hematopoeze, v procesu hojení ran, v renální fyziologii, v nádorové a reprodukční biologii., The lipocalin protein family is a large group of small extracellular proteins. The family demonstrates great diversity at sequence level; however, lipocalin crystal structures are highly conserved and comprise a single eight-stranded antiparallel β-barrel, which encloses an internal ligand-binding site. They have been associated with a variety of different functions, among them transport of retinoids, steroids, bilins, pheromones, enzymic synthesis of prostaglandins, cryptic coloration, olfaction, immune response, cell regulation. Lipocalin-2 (also known as neutrophil gelatinase-associated lipocalin), which is a useful biomarker for early detection of various renal injuries, shows pleiotropic bioactivities in a variety of different cell types and tissues. It plays important roles in angiogenesis, apoptosis, organogenesis, inflammation, hematopoiesis, wound healing, renal physiology, tumor and reproductive biology., Fořtová M., Průša R., Vajtr D., and Literatura