title: Role of p53 in the induction of cyclooxygenase-2 by cisplatin or paclitaxel in non-small cell lung cancer cell lines.
abstract: Non-small cell lung Cancer (NSCLC) is extremely resistant to chemotherapeutic agents, such as cisplatin. High expression of the inflammatory enzyme cyclooxygenase-2 (COX-2) has been shown to inhibit chemotherapy-induced apoptosis, but little is known about COX-2 regulation upon drug treatment. Recent data indicate the tumor suppressor protein p53 as an important regulator of COX-2. Therefore, TP53 status could change tumor sensitivity to chemotherapy through induction of the anti-apoptotic protein COX-2. The main objective of this work was to analyze the effect of chemotherapy on the expression of COX-2, according to TP53 status. We report herein that lung cancer cell lines expressing wild-type p53, when exposed to cisplatin treatment, induced COX-2 (mRNA and protein), with concurrent synthesis of prostaglandins (PGE(2)). In contrast, COX-2 expression was not changed after cisplatin treatment of cells containing an inactive form of p53. Further, after silencing of wild-type p53 expressed in A549 cells by RNA interference, cisplatin was no longer able to induce COX-2 expression. Therefore, we suggest that induction of COX-2 by cisplatin in NSCLC cell lines is dependent on p53. For paclitaxel treatment, an increase in COX-2 mRNA expression was observed in H460 and A549 (wild-type p53 cell lines). Moreover, paclitaxel treatment increased COX-2 expression in ACC-LC-319 cell lines (p53 null), showing a p53-independent effect. These data may have therapeutic implications in the selection of patients and strategy for future COX-2 inhibition trials.
authors.affiliation: Clinical Research Division, Research Coordenation, Instituto Nacional de Câncer, Department of Clinical Research, INCA, Rua André Cavalcanti 37/2 degrees andar, CEP 22231-050, Rio de Janeiro, Brazil.
authors.forename: Mariana Lemos
authors.initials: ML
authors.lastname: Duarte
authors.forename: Emanuela
authors.initials: E
authors.lastname: de Moraes
authors.forename: Elizangela
authors.initials: E
authors.lastname: Pontes
authors.forename: Luciene
authors.initials: L
authors.lastname: Schluckebier
authors.forename: Joyce Luana
authors.initials: JL
authors.lastname: de Moraes
authors.forename: Pierre
authors.initials: P
authors.lastname: Hainaut
authors.forename: Carlos Gil
authors.initials: CG
authors.lastname: Ferreira
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis* / Q000235:genetics; D015232:Dinoprostone / Q000378:metabolism; D004790:Enzyme Induction; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology; D009154:Mutation; D017239:Paclitaxel / Q000494:pharmacology*; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000378:metabolism; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D015232:Dinoprostone; D017239:Paclitaxel; D002945:Cisplatin