title: Enhancement of apoptosis in salivary gland cancer cells by the combination of oral fluoropyrimidine anticancer agent (S-1) and radiation.
abstract: S-1 is a new oral antineoplastic agent which can inhibit cell growth and induces apoptosis in certain types of cancer cells including gastric carcinomas, colorectal cancers and salivary gland cancers, but its effect on response of tumor cells to radiation has not been clarified yet. We have reported that S-1 can sensitize human oral cancer cells to radiation, and that S-1 in combination with radiation can exert remarkable effects on decreasing clonogenic survival and in vivo tumor growth. Here, we demonstrate the mechanism of apoptosis enhancing activity by the combination treatment of S-1 and radiation in salivary gland cancer cells. S-1 in combination with radiation have a remarkable effect on decreasing in vitro cell growth. In addition, the combined treatment of S-1 and radiation resulted in an increased DNA fragmentation by detecting Hoechst 33258 staining. Moreover, apoptosis of the cells by combined treatment of S-1 and radiation was associated with reactive oxygen/nitrogen species generation and the activation of caspase-8, -9 and -3. These results indicate that S-1 in combination with radiation can markedly enhance apoptosis of salivary gland cancer cells, and the combined therapy of S-1 and radiation are currently leading to the design of clinical studies.
authors.affiliation: Second Department of Oral and Maxillofacial Surgery, University of Tokushima, School of Dentistry, 3-18-15 Kuramoto-cho, Tokushima 770-8504, Japan. harako@dent.tokushima-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Harada
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Kawaguchi
authors.lastname: Supriatno
authors.forename: Tomitaro
authors.initials: T
authors.lastname: Onoue
authors.forename: Hideo
authors.initials: H
authors.lastname: Yoshida
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Sato
mesh_terms: D000284:Administration, Oral; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D004338:Drug Combinations; D006801:Humans; D010094:Oxonic Acid / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D012468:Salivary Gland Neoplasms / Q000473:pathology / Q000628:therapy*; D005641:Tegafur / Q000494:pharmacology*
chemical_list: D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; D011725:Pyridines; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid; D020169:Caspases