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Matične stanice raka su stanice raka koje imaju karakteristike zdravih matičnih stanica u ljudskom organizmu. Mogućnost samoobnavljanja i diferencijacije u različite tipove stanica osiguravaju im tumorigenost, dok niska stopa proliferacije uz aktivne membranske pumpe i enzime popravka osigurava otpornost na konvencionalne kemoterapeutike. Njihova prisutnost je dokazana u osteosarkomima te se mogu izdvojiti iz tumorske mase na osnovi sposobnosti rasta u sferama - sarkosferama. S obzirom da se radi o izuzetno malignim tumorima, razvoj specifičnih terapija koje ciljaju tu populaciju stanica neophodan je za poboljšanje preživljenja pacijenata. S obzirom na njihove mehanizme otpornosti teško ih je selektivno ciljati. Ovim istraživanjem ispitan je utjecaj askorbinske kiseline na matične stanice osteosarkoma te njezina selektivnost u ovisnosti o koncentraciji askorbinske kiseline te broju i porijeklu stanica. Djelovanje askorbinske kiseline utvrdili smo testovima vijabilnosti, esejom inhibicije rasta sarkosfera, protočnim citometrom, western blotom i mjerenjem razine reaktivnih kisikovih vrsta. Zaključno, askorbinska kiselina uzrokuje apoptozu te je njena letalna koncentracija ovisna o broju matičnih stanica osteosarkoma. Također, razina GAPDH proteina je nedetektibilna što ukazuje na inhibiciju glikolize. Razina reaktivnih kisikovih vrsta povišena je kod stanica tretiranih askorbinskom kiselinom te se može zaključiti da djeluje kao oksidans. Cancer stem cells are cancer cells that have the characteristics of healthy stem cells in the human body. The possibility of self-replication and differentiation in different cell types ensures their tumorigenicity while low proliferation rates with active membrane pumps and repair enzymes provide resistance to conventional chemotherapy. Their presence is proven in osteosarcoma and can be extracted from tumor mass based on the ability to grow in spheres - sarcospheres. Given that it is an extremely malignant tumor, the development of specific therapies targeting that population of cells is necessary to improve patient survival. Due to their resistance mechanisms, it is difficult to selectively target them. This study investigated the effect of ascorbic acid on osteosarcoma stem cells and its selectivity depending on the concentration of ascorbic acid and the number and origin of cells. The effects of ascorbic acid have been determined by viability tests, sarcosphere growth inhibition assays, flow cytometry, western blot and measurement of reactive oxygen species. In conclusion, ascorbic acid causes apoptosis and its lethal concentration is dependent on the number of osteosarcoma stem cells. Also, the level of GAPDH protein is undetectable, which suggests that ascorbic acid inhibits the pathway of glycolysis. The level of reactive oxygen species is increased in cells treated with ascorbic acid and it can be concluded that it acts as an oxidant. |
