15-deoxy-Delta12,14-prostaglandin J2 up-regulates death receptor 5 gene expression in HCT116 cells: involvement of reactive oxygen species and C/EBP homologous transcription factor gene transcription.
Although 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)) was reported to up-regulate death receptor 5 (DR5) protein expression and sensitize TRAIL-induced cytotoxicity, its action mechanism remains unclear. Using HCT116 colon cancer cells, we found that sensitization of TRAIL-induced cytotoxicity by 15dPGJ(2) resulted from up-regulation of DR5 via gene transcription but was not associated with PPAR-gamma activation. Moreover, 15dPGJ(2) induced GRP78, XBP1, and C/EBP homologous transcription factor (CHOP) expression in HCT116 cells, confirming that 15dPGJ(2) is an endoplasmic reticulum stress inducer. Knockdown of the CHOP gene by siRNA attenuated DR5 up-regulation and the sensitized cytotoxicity in colon cancer HCT116 and SW480. With deletion plasmids of DR5 promoters, we found that the CHOP-binding site was involved in activating the DR5 gene by 15dPGJ(2). A mechanistic study showed the contributions of reactive oxygen species (ROS) and intracellular calcium in CHOP and DR5 gene up-regulation. 15dPGJ(2) was also found to induce DR5 in two prostate cancer cell lines, LNCaP and PC3. Although in LNCaP DR5 up-regulation was accompanied by CHOP expression by 15dPGJ(2), no significant increase in CHOP expression or DR5 promoter activity was observed in PC3 cells. Intriguingly, 15dPGJ(2) induced ROS and calcium production in PC3 cells. This inability to induce CHOP was not due to the p53-null in PC3 cells, as similar extents of increase in CHOP protein were found due to 15dPGJ(2) in both wild-type and p53-null HCT116 cells. In summary, the effect of up-regulation of DR5 by 15dPGJ(2) in colon cancer cells is independent of PPAR-gamma and p53 but relies on CHOP induction through gene transcription involving ROS and calcium.
Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Rong-Ying
RY
Su
Kwan-Hwa
KH
Chi
Duen-Yi
DY
Huang
Ming-Hui
MH
Tai
Wan-Wan
WW
Lin
D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D003110:Colonic Neoplasms / Q000235:genetics / Q000473:pathology; D004354:Drug Screening Assays, Antitumor; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000473:pathology; D000091342:Endoplasmic Reticulum Chaperone BiP; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D045325:HCT116 Cells; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D047495:PPAR gamma / Q000378:metabolism; D015230:Prostaglandin D2 / Q000031:analogs & derivatives* / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology; D051742:Transcription Factor CHOP / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*
C097240:15-deoxy-delta(12,14)-prostaglandin J2; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D047495:PPAR gamma; D017382:Reactive Oxygen Species; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; D016159:Tumor Suppressor Protein p53; D051742:Transcription Factor CHOP; D015230:Prostaglandin D2; D002118:Calcium