Hydrogen sulfide (HS) is endogenously synthesized from l-cysteine in reactions catalyzed by cystathionine beta-synthase (CBS, EC 4.2.1.22) and gamma-cystathionase (CSE, EC 4.4.1.1). The role of 3-mercaptopyruvate sulfurtransferase (MPST, EC 2.8.1.2) in HS generation is also considered; it could be important for tissues with low CTH activity, e.g. cells of the nervous system. The expression and activity of CBS, CTH, and MPST were detected in the human glioblastoma-astrocytoma (U-87 MG) and neuroblastoma (SHSY5Y) cell lines. In both cell lines, the expression and activity of MPST were the highest among the investigated enzymes, suggesting its possible role in the generation of HS. The RP-HPLC method was used to determine the concentration of cystathionine and alpha-ketobutyrate, products of the CBS- and CTH-catalyzed reactions. The difference in cystathionine levels between cell homogenates treated with totally CTH-inhibiting concentrations of dl-propargylglycine and without the inhibitor was used to evaluate the activity of CBS. The higher expression and activity of CBS, CTH and MPST in the neuroblastoma cells were associated with more intensive generation of HS in the presence of 2 mM cysteine. A threefold higher level of sulfane sulfur, a potential source of hydrogen sulfide, was detected in the astrocytoma cells in comparison to the neuroblastoma cells.

Many of the current anticancer therapies rely on the induction of apoptosis, and several mechanisms that protect cells against apoptosis may be upregulated in tumors. A growing body of evidence suggests that single drugs with a clearly defined intracellular target may be less efficient in arresting tumor growth and induction of apoptosis than multitargeted strategies. To prove that this is also the case for melanoma, we studied five cell lines, which represent different stages of tumor progression. We tested cell viability, terminal dUTP nick-end labeling and activation of caspase-3 upon exposure to cytochalasin D, LY294002 and olomoucine, added either alone or in various combinations. The obtained data were compared with effects caused by staurosporine. The results show that whereas staurosporine efficiently induced apoptosis in all tested melanoma cell lines, the other drugs had only moderate effects when administered alone. In contrast, the combinations of drugs were more effective in inducing caspase-3 activity and reducing cell viability. In particular, the triple combination of cytochalasin D+LY294002+olomoucine was almost as effective as staurosporine in inducing caspase-3 activity and apoptosis. These results prove that it is possible to design new pharmacological strategies that will effectively induce caspase-3 activity and apoptosis in melanoma. The possible explanations of the observed synergy between the tested drugs are also discussed.

The S-Allyl-L-cysteine (SAC) component of aged garlic extract (AGE) is proven to have anticancer, antihepatotoxic, neuroprotective and neurotrophic properties. γ-Cystathionase (CTH), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (MPST) are involved in H2S/sulfane sulfur endogenous formation from L-cysteine. The aim of the study was to determine the effect of SAC on MCF-7 cells survival and apoptosis, which is a widely known approach to reduce the number of cancer cells. An additional goal of this paper was to investigate the effect of SAC on the activity and expression of enzymes involved in H2S production. The experiments were carried out in the human breast adenocarcinoma cell line MCF-7. Changes in the cell viability were determined by MTT assay. Cell survival was determined by flow cytometry (FC). Changes in enzymes expression were analyzed using Western blot. After 24 h and 48 h incubation with 2245 µM SAC, induction of late apoptosis was observed. A decrease in cell viability was observed with increasing SAC concentration and incubation time. SAC had no significant cytotoxic effect on the MCF-7 cells upon all analyzed concentrations. CTH, MPST and CBS expression were confirmed in non-treated MCF-7 cells. Significant decrease in MPST activity at 2245 µM SAC after 24 h and 48 h incubation vs. 1000 µM SAC was associated with decrease in sulfane sulfur levels. The presented results show promising SAC effects regarding the deterioration of the MCF-7 cells’ condition in reducing their viability through the downregulation of MPST expression and sulfate sulfur level reduction.

BackgroundFarnesyltransferase inhibitor tipifarnib (R115777) has been used for treatment of hematological malignancies; however, its observed anticancer effect was limited. This prompted us to search for inhibitors that would show synergic, proapoptotic effect when combined with R115777. We decided to study LY294002, which inhibits PI-3 kinase, and tanespimycin (17AAG), which inhibits Hsp90—a chaperone for a number of proteins, including Akt kinase.MethodsThe effect of drugs, used alone or in combination, was tested in U937 cells (human leukemic monocyte lymphoma), which are often used as a model for liquid tumor. The number of viable cells was evaluated with trypan blue staining, while apoptosis was assessed by presence of active caspase-3 and terminal dUTP nick-end labeling of DNA (TUNEL).ResultsAt concentrations in which R115777, LY294002 and 17AAG were only slowing down the proliferation rate, when used separately, the combination of R115777 + LY294002 and R115777 + 17AAG significantly reduced the number of cells and induced cellular apoptosis.ConclusionsOur results suggest that the combination of R115777 + 17AAG could be useful in treating some of the hematological malignancies.

Many anticancer strategies rely on efficient induction of apoptosis. The need for development of drug combinations with a strong pro-apoptotic activity is of particular interest in melanoma resistant to currently available chemotherapeutic regimes. We studied the pro-apoptotic properties of combination of tanespimycin+tipifarnib in five melanoma cell lines representing various stages of tumor progression. Our results show that in cells derived from vertical- and metastatic-phase the combination of tested drugs is strongly cytotoxic and efficient in inducing apoptosis, as evidenced by activation of caspase-9 and caspase-3 and enhanced fragmentation of DNA.

Aktywne zaangażowanie studentów w proces uczenia się i zdobywania wiedzy sprawia, że nauka rozwija ich pasje i umiejętności. Celem nauczania powinno być zwiększenie liczby zaangażowanych i zadowolonych z procesu uczenia się studentów. Pozytywne efekty można osiągnąć przez stworzenie atrakcyjnych i przystępnych warunków do nauki. Poszukiwanie technik zwiększających zaangażowanie studentów, wprowadzanie nowych metod dydaktycznych i edukacja nakierowana na studenta powinny być stałymi elementami współczesnego nauczania. Szczególne wyzwanie stanowią krótkie kursy, zwłaszcza te z niewielką liczbą uczestników. Słuchacze takiego kursu są mocno zróżnicowani pod względem bazowego przygotowania merytorycznego. W małym zespole łatwo wyodrębnić podgrupy z różnymi oczekiwaniami wobec kursu. Chcąc zainteresować wszystkich słuchaczy, należy wdrażać i stosować szereg nowoczesnych, aktywnych metod dydaktycznych. Dzięki temu osiągniemy zarówno założone dla kursu efekty kształcenia, a co za tym idzie – zaliczenie przedmiotu, jak i satysfakcję studentów. Jednak najważniejszym celem kursu jest dla studenta nabycie umiejętności i wiedzy, które będą dla niego przydatne i rozwijające. Celem artykułu jest opis zmian planowanych w kursie „Biochemia z elementami chemii” na kierunku Ratownictwo Medyczne. Artykuł koncentruje się na przedstawieniu propozycji technik edukacyjnych, które wyrównają szanse w nauce wśród wszystkich studentów (ang. equal learning experience). Planowane modyfikacje pozwolą zwiększyć satysfakcję edukatorów z nauczania, a studentów z uczenia się. Podstawową zmianą koncepcji kursu będzie przejście z powszechnego prezentowania informacji i transferu wiedzy na linii nauczyciel – student na uczenie skoncentrowane na uczniu i jego aktywnym udziale w zajęciach. Planowane jest wprowadzenie nauczania zdalnego z użyciem platform e-learningowych i dostępnych narzędzi do interaktywnego uczenia online (ang. interactive learning tools), takich jak polleverywhere (https://www.polleverywhere.com/) czy perusall (https://perusall.com/inactivity). Wprowadzone zostaną techniki nauczania opartego na przypadku (ang. case based learning, CBL), techniki aktywizacji osadzone w kontekście przyszłego zawodu ratownika medycznego, jak np. odgrywanie ról (ang. role playing), krytyczna analiza wyników czy sporządzanie raportów.