title: Alteration in TWIST expression: possible role in paclitaxel-induced apoptosis in human laryngeal carcinoma Hep-2 cell line.
abstract: OBJECTIVE
  To explore the relationship between alteration in the expression of TWIST, highly conserved transcription factor from the basic helix-loop-helix family, and apoptosis of Hep-2 cells induced by chemotherapeutic agent paclitaxel.
  
  
  METHODS
  Morphological changes of Hep-2 cells were observed by acridine orange cytochemistry staining. Viability of Hep-2 cells treated with various concentrations of paclitaxel was examined by cell proliferation assay. Apoptosis was examined by flow cytometry. The mRNA and protein expression of TWIST in response to paclitaxel at 24 hours, 48 hours, and 72 hours was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively.
  
  
  RESULTS
  Typical morphological changes of apoptotic cells at 24 hours, 48 hours, or 72 hours after treatment wiyth paclitaxel (10x10(-9) mol/L) were observed. The cell survival rates significantly decreased in a concentration- and time-dependent manner (P=0.001). Paclitaxel-induced apoptosis increased with culture time (22.6+/-5.3% after 24 hours, 38.7+/-7.9% after 48 hours, and 52.4+/-14.3% after 72 hours; P=0.002). Both mRNA and protein expression of TWIST was markedly decreased at both mRNA levels and protein levels, at 24 hours, 48 hours, and 72 hours in the paclitaxel-induced apoptosis of Hep-2 cells (P<0.001).
  
  
  CONCLUSIONS
  TWIST, which has a significantly decreased expression in response to paclitaxel in Hep-2 cells, may play a pivotal role in paclitaxel-induced apoptosis of Hep-2 cells.
authors.affiliation: Department of Otolaryngology and Head and Neck Surgery, Provincial Hospital affiliated to Shandong University, Jinan, 250021, Peoples' Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yu
authors.forename: Hui-Zheng
authors.initials: HZ
authors.lastname: Li
authors.forename: Su-Mei
authors.initials: SM
authors.lastname: Lu
authors.forename: Wen-Wen
authors.initials: WW
authors.lastname: Liu
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Li
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002277:Carcinoma / Q000188:drug therapy*; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000188:drug therapy*; D017239:Paclitaxel / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051879:Twist-Related Protein 1 / Q000096:biosynthesis* / Q000502:physiology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D012333:RNA, Messenger; D051879:Twist-Related Protein 1; D017239:Paclitaxel