Pleurotus ostreatus에서 분리한 ostreolysin에 의한 FaDu 하인두 편평 세포암의 세포사멸 유도

Abstract

There is a common saying, ‘'Medicines and foods have a common origin’'. Edible mushrooms are a manifestation of this idea in constituting both a nutritionally functional food and a source of physiologically beneficial medicine. in several centuries ago, medicinal properties of edible mushrooms have been recognized in Korea. Although from ancient times, edible mushrooms have been treated as a special kind of functional foods, they have received a remarkable interest in recent decades. Major medicinal properties attributed to edible mushrooms includes anticancer activity, antibiotic activity, antiviral activity, immune responsestimulating effects, anti-hypertensive and blood lipid lowering effects. Some edible mushrooms have gained special consideration due to their various medicinal values in addition to high nutritional value. For example, Lentinus edodes were reported to possess anti-tumor, antihypertensive, hypocholesterolemic and antibacterial activities. The betaglucan polysaccharide has potential application in immune surveillance and chemoprevention of cancer. Furthermore, ostreolysin, an acidic, 15 kDa protein from the edible oyster mushroom such as Pleurotus ostreatus (P. ostreatus), is a toxic, pore-forming cytolysin from cancer cells. To explore its potential anti-cancer effect on FaDu human hypopharyngeal squamous carcinoma cells, we examined whether the purified ostreolysin from P. ostreatus could inhibit the growth of FaDu human hypopharyngeal squamous carcinoma cells and investigated molecular mechanism of anti-cancer activity. Purification was performed by size exclusion gel filtration in Fast Protein Liquid Chromatography (FPLC) using Superdex 200 100/300 column. FaDu human hypopharyngeal squamous carcinoma cells were treated with different concentrations of ostreolysin purified from P. ostreatus for 24 hours. Then, the cell viability was determined using colorimetric MTT assay. Ostreolysin (15 kDa) purified from P. ostreatus caused a significant inhibition on the growth of cancer cells in a dose-dependent manner. To understand of molecular mechanism whether its cell death is related with apoptosis pathway, we performed DNA fragmentation assay. The formation of a DNA ladder was observed by treatment of ostreolysin (15 kDa) purified from P. ostreatus. In addition, western blot analysis showed that ostreolysin (15 kDa) purified from P. ostreatus decreased the pro-caspase 9, 3, and activated cleaved PARP. These results might suggest of adjuvant chemotherapy that the ostreolysin (15 kDa) purified from P. ostreatus induced cell apoptosis through mitochondrial caspases dependent pathway in FaDu human hypopharyngeal squamous carcinoma cells.