title: Basic helix-loop-helix transcription factor DEC2 functions as an anti-apoptotic factor during paclitaxel-induced apoptosis in human prostate cancer cells.
abstract: The functions of basic helix-loop-helix (bHLH) transcription factor-differentiated embryonic chondrocyte (DEC)1 (BHLHE40) and 2 (BHLHE41) are involved in various fields such as circadian rhythms, immune responses, cell proliferation, hypoxia reaction as well as malignant tumors. Previous findings showed that DEC served as apoptosis regulators of various cancer cell lines. However, little is known regarding the expression of DEC1 and DEC2 in prostate cancer cells. The present study aimed to examine the roles of DEC1 and DEC2 in human prostate cancer DU145 and PC-3 cells that were treated with paclitaxel. The expression of DEC1 and DEC2 was decreased in DU145 cells but was increased in PC-3 cells when treated with paclitaxel. DU145 cells were more sensitive to paclitaxel than PC-3 cells since the amount of cleaved poly(ADP-ribose) polymerase (PARP) reached its peak at 50 µM of paclitaxel in DU145 cells but at 100 µM in PC-3 cells. In addition, the amount of cleaved PARP was decreased by DEC1 siRNA, while it was increased by DEC2 siRNA in the presence of paclitaxel. Although DEC2 overexpression slightly inhibited cleaved PARP in the two cell lines, the effects of DEC1 overexpression on apoptosis remain to be determined. In conclusion, DEC1, at least partly, exerted a pro-apoptotic effect, whereas DEC2 exerted an anti-apoptotic effect in paclitaxel-induced apoptosis of human prostate cancer cells.
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Yunyan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshizawa
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Xu
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Morohashi
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Seino
authors.affiliation: Department of Dental and Medical Biochemistry, Hiroshima University Graduate School of Biomedical Science, Hiroshima 734-8553, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Pathology and Bioscience, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kijima
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006801:Humans; D008297:Male; D017239:Paclitaxel / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D051792:Basic Helix-Loop-Helix Proteins; D015415:Biomarkers; D017239:Paclitaxel; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; C422085:BHLHE41 protein, human; C403671:DELEC1 protein, human