caa a22 4500 606235213 CHVBK 20210128101241.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s11010-015-2488-x doi (NATIONALLICENCE)springer-10.1007/s11010-015-2488-x Synergistic anticancer effects of combined γ-tocotrienol and oridonin treatment is associated with the induction of autophagy [Elektronische Daten] [Roshan Tiwari, Parash Parajuli, Paul Sylvester] γ-Tocotrienol and oridonin are natural phytochemicals that display potent anticancer activity. Studies showed that combined treatment with subeffective doses of γ-tocotrienol with oridonin resulted in synergistic autophagic and apoptotic effects in malignant +SA, but not normal CL-S1 mouse mammary epithelial cells in vitro. Specifically, combined treatment with low doses of γ-tocotrienol (8µM) and oridonin (2µM) for 24h resulted in synergistic inhibition of +SA mammary cancer cells viability. This combination significantly enhanced the expression of autophagy cellular markers including the conversion of LC3B-I to LC3B-II, beclin-1, Atg3, Atg7, Atg5-Atg12, LAMP-1 and cathepsin-D, and pretreatment with the autophagy inhibitors 3-methyladenine (3-MA) or bafilomycin A1 (Baf1) blocked these effects. Furthermore, blockade of γ-tocotrienol and oridonin-induced autophagy with 3-MA or Baf1 induced a modest, but significant reduction in cytotoxicity resulting from the combined treatment of these phytochemicals. The anticancer effects of combination treatment was also associated with a large suppression in Akt/mTOR mitogenic signaling and corresponding increase in the levels of apoptotic cellular marker including cleaved caspase-3 and PARP, and Bax/Bcl-2 ratio in these tumor cells. These effects were also found to be selective against cancer cells, since similar combined treatment with γ-tocotrienol and oridonin did not induce autophagy or reduce viability of normal mouse CL-S1 mammary epithelial cells. These findings indicate that combined γ-tocotrienol and oridonin-induced autophagy plays a role in mediating the synergistic anticancer effects of these phytochemicals. Springer Science+Business Media New York, 2015 γ-Tocotrienol nationallicence Autophagy nationallicence Breast cancer nationallicence Beclin-1 nationallicence LAMP-1 nationallicence Cathepsin-D nationallicence Tiwari Roshan School of Pharmacy, University of Louisiana at Monroe, 700 University Avenue, 71209, Monroe, LA, USA aut Parajuli Parash School of Pharmacy, University of Louisiana at Monroe, 700 University Avenue, 71209, Monroe, LA, USA aut Sylvester Paul School of Pharmacy, University of Louisiana at Monroe, 700 University Avenue, 71209, Monroe, LA, USA aut Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 408/1-2(2015-10-01), 123-137 0300-8177 408:1-2<123 2015 408 11010 https://doi.org/10.1007/s11010-015-2488-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11010-015-2488-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tiwari Roshan School of Pharmacy, University of Louisiana at Monroe, 700 University Avenue, 71209, Monroe, LA, USA aut NATIONALLICENCE 700 1- Parajuli Parash School of Pharmacy, University of Louisiana at Monroe, 700 University Avenue, 71209, Monroe, LA, USA aut NATIONALLICENCE 700 1- Sylvester Paul School of Pharmacy, University of Louisiana at Monroe, 700 University Avenue, 71209, Monroe, LA, USA aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 408/1-2(2015-10-01), 123-137 0300-8177 408:1-2<123 2015 408 11010