title: Acetylshikonin inhibits growth of oral squamous cell carcinoma by inducing apoptosis.
abstract: OBJECTIVE
  Recently, shikonin derivatives from Lithospermum erythrorhizon have been suggested as potential chemotherapeutic agents against numerous types of cancers in addition to their traditional uses, e.g., as anti-inflammatory agents. Acetylshikonin, one of shikonin derivatives, has also been reported to possess anticancer activity. However, few studies of the effectiveness of acetylshikonin against cancer cells have been conducted, and there are no studies of oral cancers. In this study, we investigated the usefulness of acetylshikonin as a treatment regimen for oral cancers by observing the growth inhibitory function of acetylshikonin and the involved mechanisms.
  
  
  METHODS
  The viability, cell cycle, and ratio of apoptotic cells of oral squamous cell carcinoma (OSCC) cells were observed after treatment with acetylshikonin using MTT assay, flow cytometric analysis, and Annexin V/PI staining, respectively. In addition, molecular changes of apoptosis-related pathways and the role of reactive oxygen species (ROS) were analyzed in acetylshikonin-treated cells.
  
  
  RESULTS
  We observed that acetylshikonin significantly suppressed the growth of OSCC cells by inducing apoptotic cell death, and acetylshikonin affected the viability of a normal keratinocyte cell line HaCaT to a lesser degree, suggesting that acetylshikonin may be a good chemotherapeutic reagent with less toxicity to normal tissues. In addition, we found that acetylshikonin-induced apoptosis of OSCC cells is mediated by ROS as well as G2 cell cycle arrest. ROS production in response to acetylshikonin treatment enhanced the phosphorylation of JNK and p38 MAPK, which are in the major pathways of apoptotic cell death mechanisms.
  
  
  CONCLUSIONS
  In summary, our data suggest that acetylshikonin is a strong candidate for use as a selective chemotherapeutic agent for the treatment of OSCC.
authors.affiliation: Department of Oral Pathology & BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, South Korea; School of Dentistry, Pusan National University, 49 Busandaehak-Ro, Yangsan 626-870, South Korea.
authors.forename: Da Jeong
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Oral Pathology & BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, South Korea; School of Dentistry, Pusan National University, 49 Busandaehak-Ro, Yangsan 626-870, South Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Oral Pathology & BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, South Korea; School of Dentistry, Pusan National University, 49 Busandaehak-Ro, Yangsan 626-870, South Korea; Institute of Translational Dental Sciences, Pusan National University, 49 Busandaehak-Ro, Yangsan 626-870, South Korea. Electronic address: parkhr@pusan.ac.kr.
authors.forename: Hae Ryoun
authors.initials: HR
authors.lastname: Park
authors.affiliation: Department of Horticultural Bioscience, Pusan National University, Samnangjin-Ro 1268-50, Samnangjin-eup, Miryang 627-706, South Korea. Electronic address: ywchoi@pusan.ac.kr.
authors.forename: Young Whan
authors.initials: YW
authors.lastname: Choi
mesh_terms: D000880:Anthraquinones / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000880:Anthraquinones; D000970:Antineoplastic Agents; D017382:Reactive Oxygen Species; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; C073944:acetylshikonin
keywords: Acetylshikonin; Apoptosis; Oral cancer; Oral squamous cell carcinoma; Reactive oxygen species