Cyclooxygenase-2 (COX-2) is an important enzyme in inflammation. In this study, we investigated the underlying molecular mechanism of the synergistic effect of rottlerin on interleukin1β (IL-1β)-induced COX-2 expression in MDA-MB-231 human breast cancer cell line. Treatment with rottlerin enhanced IL-1β-induced COX-2 expression at both the protein and mRNA levels. Combined treatment with rottlerin and IL-1β significantly induced COX-2 expression, at least in part, through the enhancement of COX-2 mRNA stability. In addition, rottlerin and IL-1β treatment drove sustained activation of p38 Mitogen-activated protein kinase (MAPK), which is involved in induced COX-2 expression. Also, a pharmacological inhibitor of p38 MAPK (SB 203580) and transient transfection with inactive p38 MAPK inhibited rottlerin and IL-1β-induced COX-2 upregulation. However, suppression of protein kinase C δ (PKC δ) expression by siRNA or overexpression of dominant-negative PKC δ (DN-PKC-δ) did not abrogate the rottlerin plus IL-1β-induced COX-2 expression. Furthermore, rottlerin also enhanced tumor necrosis factor-α (TNF-α), phorbol myristate acetate (PMA), and lipopolysaccharide (LPS)-induced COX-2 expression. Taken together, our results suggest that rottlerin causes IL-1β-induced COX-2 upregulation through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells.
Cyclooxygenase (COX) is the rate-limiting enzyme that catalyzes arachidonic acid into prostanoids and has two subtypes, COX-1 and COX-2. COX-1 is constitutively expressed in tissues and is thought to be involved in homeostatic prostanoid biosynthesis, while COX-2 is expressed in the cytoplasm and its expression is inducible during inflammatory processes (Griswold and Adams, 1996; Smith et al., 2000; Tsatsanis et al., 2006). According to the several previous reports, COX-2 expression is upregulated by diverse agents and is mediated by Mitogen-activated protein kinases (MAPKs), reactive oxygen species (ROS), AP-1 or NF-κB (Mifflin et al., 2004; Shishodia et al., 2004; Song et al., 2007; Chandramohan et al., 2008; Jaimes et al., 2008; Kim et al., 2009; Chiu et al., 2010). Upregulation of COX-2 has been linked to the progression of tumors, resistance to cell death and the metastatic phenotype of human cancer cells (Chen et al., 2001; Denkert et al., 2004; Brown and DuBois, 2005). The p38 Mitogen-activated protein kinase (MAPK) plays a crucial role in inflammation (Schieven, 2005). Activated p38 MAPK upregulates the production of key inflammatory mediators, including TNF-α, IL-1β and COX-2, by several independent mechanisms, including direct phosphorylation of transcription factors, direct or indirect mRNA stabilization and enhanced translation of mRNAs in various cell types (Ridley et al., 1998; Molina-Holgado et al., 2000; Mifflin et al., 2002, 2004; Di Mari et al., 2007).
Rottlerin, which is a pigmented plant compound isolated compound from Mallotus philippinensis, was originally identified as a specific inhibitor of the novel protein kinase C (PKC) isoform, PKC δ (Gschwendt et al., 1994; Cross et al., 2000; Kontny et al., 2000; Hsieh et al., 2007). PKC δ activation and translocation are induced by a variety of inflammatory stimuli (Abad et al., 2006). However, some recent studies showed that rottlerin was not effective at inhibiting PKC δ activity in vitro and that may display non-specific effects (Soltoff, 2007; Song et al., 2008; Lim et al., 2009; Park et al., 2010).
In this study, we investigated whether rottlerin affects IL-1β-induced COX-2 expression in breast cancer cells. Combined treatment with rottlerin and IL-1β-induced COX-2 upregulation is correlated with COX-2 mRNA stability. Sustained activation of p38 MAPK is involved in rottlerin and IL-1β-induced COX-2 expression. However, the suppression of PKC δ expression by siRNA did not abrogate rottlerin and IL-1β-induced COX-2 expression. Furthermore, other inflammatory stimuli such as, TNF-α, PMA, and LPS, also upregulate COX-2 expression in the presence of rottlerin.
Rottlerin enhances IL-1β-induced COX-2 expression in MDA-MB-231 cells
IL-1β is an important inflammatory cytokine that induces COX-2 expression in various cells (Molina-Holgado et al., 2000; Jung et al., 2003). To test whether rottlerin affects IL-1β-induced COX-2 expression, MDA-MB-231 cells were treated with IL-1β (5 ng/ml) and various concentrations (1-5 µM) of rottlerin for 12 h. As shown in Figure 1A, IL-1β alone slightly induces COX-2 protein expression. Interestingly, co-treatment of MDA-MB-231 cells with rottlerin and IL-1β resulted in a markedly increased COX-2 expression (Figure 1A). To elucidate the relationship between COX-2 protein and COX-2 mRNA in MDA-MB-231 cells, we performed RT-PCR. The levels of COX-2 mRNA also dramatically increased after combined treatment with rottlerin and IL-1β (Figure 1B). Additionally, incubation with rottlerin (2.5 µM) enhanced IL-1β-induced COX-2 protein and mRNA levels at low concentrations of IL-1β (Figures 1C and 1D).
MAPK signaling pathway activation following rottlerin and IL-1β treatment
To investigate whether the ERK, JNK, or p38 MAPK pathways are involved in rottlerin and IL-1β-induced COX-2 expression, we examined whether selective MAPK inhibitors could affect rottlerin plus IL-1β-induced COX-2 expression. Induction of the COX-2 protein and mRNA expression was dramatically reduced in the presence of p38 MAPK inhibitor (SB 203580), while JNK inhibitor (SP 600125) was ineffective at regulating COX-2 expression. Treatment with MEK1/2 inhibitor (PD 098059) slightly inhibited COX-2 protein and mRNA expression. Because the p38 MAPK inhibitor markedly inhibited COX-2 expression, we assessed the activation of p38 MAPK by detecting its dually phosphorylated form using Western blotting with specific anti-phospho-p38 MAPK antibodies in MDA-MB-231 cells treated with IL-1β alone, rottlerin alone or rottlerin plus IL-1β (Figure 2C). IL-1β (5 ng/ml) treatment induces a strong transient increase in phosphorylated p38 MAPK level, that peaked at 30 min and declined thereafter. Treatment with rottlerin (2.5 µM) alone slightly increases the phosphorylation of p38 MAPK. Interestingly, phosphorylation levels of p38 MAPK were sustained for 90 min after combined treatment with rottlerin and IL-1β.
Recently, several groups reported that the p38 MAPK pathway significantly contributes to COX-2 mRNA stability (Huang et al., 2000; Tsatsanis et al., 2006). We examined the effect of combined treatment with rottlerin and IL-1β on the COX-2 mRNA stability. To measure COX-2 mRNA stability following rottlerin and IL-1β treatment, MDA-MB-231 cells were treated with rottlerin (2.5 µM) and IL-1β (5 ng/ml) for 12 h to induce COX-2 transcription and then further cultured with or without rottlerin plus IL-1β in the presence of actinomycin D (2.5 µg/ml). As shown in Figure 2D, treatment with rottlerin plus IL-1β enhances the half-life of COX-2 mRNA. Together, these data suggest that rottlerin and IL-1β treatment enhances COX-2 expression at least in part through the sustained activation of p38 MAPK-mediated COX-2 mRNA stability.
p38 MAPK signaling pathway is involved in rottlerin plus IL-1β-induced COX-2 expression in MDA-MB-231 cells
To explore the significance of p38 MAPK in rottlerin plus IL-1β-induced COX-2 expression, we first examined the dose effect of SB 203580 on COX-2 expression. As shown in Figures. 3A and 3B, pretreatment with SB 203580 inhibited rottlerin plus IL-1β-induced expression of COX-2 protein and mRNA in a dose-dependent manner. To further evaluate that the role of the p38 MAPK in rottlerin plus IL-1β-induced COX-2 expression, we transiently transfect MDA-MB-231 cells with vector, wild-type p38 MAPK or p38 MAPK-DN (a dominant negative mutant). As shown in Figure 3C, ectopic expression of p38 MAPK-DN decreased COX-2 expression levels in the presence of rottlerin and IL-1β. These results suggest that rottlerin plus IL-1β-induced COX-2 expression was modulated, at least, by the p38 MAPK signaling pathway.
ROS generation and NF-κB activity were not affected by rottlerin plus IL-1β-induced COX-2 expression
Previous studies have demonstrated that COX-2 induction is stimulated by reactive oxygen species (ROS) generation in several cell lines (Feng et al., 1995; Jaimes et al., 2008). Therefore, we examined whether ROS generation might be involved in rottlerin plus IL-1β-induced COX-2 expression. As shown in Figures 4A and 4B, pretreatment with antioxidants N-acetylcysteine (NAC) or glutathione (GSH) did not affect rottlerin plus IL-1β-induced expression levels of COX-2 protein and mRNA. In addition, we tested whether rottlerin plus IL-1β-induced COX-2 expression was associated with NF-κB activity. As shown in Figures 4C and 4D, pretreatment with NF-κB inhibitor MG132 or BAY 11-7082 did not affect rottlerin plus IL-1β-induced expression levels of COX-2 protein and mRNA. These results suggest that rottlerin plus IL-1β-induced COX-2 expression is independent of ROS generation and NF-κB signaling.
Rottlerin plus IL-1β-induced COX-2 expression is independent of PKC δ inhibition
Rottlerin is identified as a putative inhibitor of PKC δ (Gschwendt et al., 1994), thus we examined whether rottlerin plus IL-1β-induced COX-2 expression was directly associated with the inhibition of PKC δ activity. We employed a siRNA duplex against PKC δ mRNA. MDA-MB-231 cells transfected with the control or PKC δ siRNA and treated with IL-1β (10 ng/ml) for 12 h. Suppression of PKC δ expression by transfection with siRNA did not upregulates IL-1β-induced COX-2 expression in MDA-MB-231 cells (Figure 5A). Additionally, to further confirm the independence of PKC δ activity, MDA-MB-231 cells were transfected with vector or PKC δ dominant negative (DN) mutant and treated with IL-1β (10 ng/ml) for 12 h. As shown in Figure 5B, ectopic expression of DN-PKC δ did not affect IL-1β-induced COX-2 expression (Figure 5B). Our results suggest that rottlerin plus IL-1β-induced COX-2 expression is independent of PKC δ pathway.
Rottlerin enhances TNF-α, PMA- and LPS-induced COX-2 expression in MDA-MB-231 cells
TNF-α, PMA and LPS have been previously shown to induce COX-2 expression (Mitchell et al., 1994; Miralpeix et al., 1997; Huang et al., 2000; Molina-Holgado et al., 2000; Nakao et al., 2002; Shishodia et al., 2004; Woo and Kwon, 2007). We carried out Western blotting and RT-PCR to test the effect of rottlerin on TNF-α-, PMA- and LPS-induced COX-2 expression in MDA-MB-231 cells. As shown in Figures 6A, 6B and 6C, treatment with rottlerin enhances TNF-α-, PMA- and LPS-induced COX-2 protein and mRNA expression. Pretreatment with a p38 inhibitor decreases COX-2 protein and mRNA expression after treatment with rottlerin plus TNF-α, PMA or LPS. These results show that rottlerin enhances COX-2 expression induced by multiple reagents.
In the present study, we demonstrate for the first time that treatment of breast cancer cells with rottlerin in combination with IL-1β markedly induces COX-2 expression. It has been reported that rottlerin is a specific inhibitor of PKC δ (Gschwendt et al., 1994), However, some recent studies showed that rottlerin might not act directly on PKC δ, but instead elicit cellular changes that mimic those caused by the direct inhibition of PKC δ (Gschwendt et al., 1994; Soltoff, 2007; Song et al., 2008; Lim et al., 2009; Park et al., 2010). Therefore, we tested the possibility that rottlerin could enhance IL-1β-induced COX-2 expression in human breast cancer cells. In this study, we demonstrate that co-treatment with rottlerin enhances IL-1β-induced COX-2 expression through sustained p38 MAPK activation in MDA-MB-231 cells. However, our results indicate that PKC δ is not involved in rottlerin plus IL-1β-induced COX-2 upregulation. This view is supported by the following findings: (a) suppression of PKC δ expression with siRNA did not upregulates IL-1β-induced COX-2 expression and (b) overexpression of DN-PKC δ did not upregulates IL-1β-induced COX-2 expression.
COX-2 is aberrantly overexpressed in many human cancers such as colon, lung, breast, and prostate cancer (Smith et al., 2000; Brown and DuBois, 2005). COX-2 gene expression is regulated by transcriptional and post-transcriptional mechanisms; the relative contribution of each mechanism is dependent on the stimulus, the cellular environment and the particular cell type. Studies that examined COX-2 transcription have shown that NF-κB, nuclear factor of interleukin-6 (NF-IL-6), cAMP response element (CRE), and AP1 were commonly or individually involved in the regulation of COX-2 expression (Dannenberg et al., 2001; Dempke et al., 2001). In addition, post-transcriptional regulation of COX-2 expression has been mainly attributed to stabilization of the COX-2 mRNA by signaling proteins (p38 MAPK, ERK, PI3K/PKB), RNA binding proteins (HuR, TTP) and AU-rich elements in the COX-2 mRNA 3'-UTR (Lasa et al., 2000). IL-1β and p38 MAPK-mediated stabilization of the COX-2 mRNA has been previously reported (Dean et al., 1999). Studies using pharmacological inhibitors of MAPKs demonstrated the role of p38 MAPK in rottlerin plus IL-1β-induced COX-2 upregulation in MDA-MB-231 cells (Figure 3A). Furthermore, the suppression of rottlerin plus IL-1β-induced COX-2 expression by overexpression of the DN-p38 MAPK (Figure 3C) is consistent with the concept that the p38 MAPK signaling pathway is important for regulating both COX-2 transcription and mRNA stability. One of the interesting findings from this study is that treatment with rottlerin enhances TNF-α-, PMA- and LPS-induced COX-2 protein and mRNA expression (Figure 6) as well as IL-1β-induced COX-2 expression. These observations suggest that rottlerin-mediated TNF-α-, PMA-, LPS-, or IL-1β-induced COX-2 upregulation via the p38 MAPK signaling pathway is a common response.
ROS play an important role in inflammatory processes as mediators of injury. Feng et al. (1995) reported that oxidant stress is a specific and important inducer in COX-2 expression induced by IL-1, TNF-α and LPS. However, in our data, pretreatment with an ROS scavenger did not suppress rottlerin plus IL-1β-induced COX-2 expression (Figure 4). Another interesting finding from this study is that NF-κB is not involved in rottlerin plus IL-1β-induced COX-2 upregulation.
In conclusion, the present study shows that COX-2 expression is regulated by rottlerin. We have provided sufficient evidence showing that p38 MAPK signaling pathways play a vital role in the regulating COX-2 expression after combined treatment with rottlerin and IL-1β in breast carcinoma cells, which may contribute to a better understanding of inflammation and cancer.
Cells and materials
MDA-MB-231 cells were obtained from the American Type Culture Collection (ATCC; Rockville, MD) and grown in Dulbecco's modified Eagle's medium (DMEM), containing 10% fetal bovine serum (FBS), 20 mM HEPES and 100 µg/ml gentamicin at 37℃ in a humidified atmosphere of 5% CO2 and 95% air. Recombinant interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) proteins were purchased from R&D systems (Minneapolis, MN). MG132, BAY 11-7082 and PMA were obtained from Calbiochem (San Diego, CA). Rottlerin, PD 98059, SB 203580, SP 600125, LY 294002 and wortmannin were purchased from BIOMOL (Plymouth Meeting, PA). Actinomycin D, glutathione (GSH), N-acetylcysteine (NAC) and lipopolysaccharides (LPS) were purchased from Sigma-Aldrich (St. Louis, MO). Anti-COX-2 antibody was obtained from the Cayman Chemical Company (Ann Arbor, MI); anti-phospho-JNK, anti-JNK, anti-phospho-p38 MAPK, anti-p38 MAPK, anti-phospho-ERK, anti-ERK, anti-phospho-AKT and anti-AKT antibodies from Cell Signaling (Danvers, MA); and anti-PKC δ antibody was purchased from BD Transduction Laboratories™ (San Diego, CA).
Cellular lysates were prepared by suspending 1.5 × 106 cells in 100 µl of lysis buffer (137 mM NaCl, 15 mM EGTA, 0.1 mM sodium orthovanadate, 15 mM MgCl2, 0.1% Triton X-100, 25 mM MOPS (4-morpholinepropane-sulfonic acid), 100 µM phenylmethylsulfonyl fluoride and 20 µM leupeptin, adjusted to pH 7.2), disrupted by sonication and extracted at 4℃ for 30 min. The proteins were electrotransferred to Immobilon-P membranes (Millipore Corp., Bedford, MA). Detection of specific proteins was carried out with an ECL Western blotting kit (Millipore Corp.) according to the manufacturer's instructions.
RNA isolation and reverse transcriptase-polymerase chain reaction (RT-PCR)
Total cellular RNA was extracted from cells using TRIzol (Invitrogen, Carlsbad, CA). Single-strand cDNA was synthesized from 2 µg of total RNA using M-MLV reverse transcriptase (Promega, Madison, WI). The cDNA for COX-2 was amplified by PCR with specific primers: 5'-CCGGAC AGGATTCTATGGAGA-3' (sense) and 5'-GAAGTGCTGG GCAAAGAATGC-3' (antisense). PCR amplification was carried out as follows: 1 × (94℃, 3 min); 25 × (94℃, 45 s; 55℃, 45 s; 72℃, 45 s); and 1 × (72℃, 10 min). PCR products were analyzed using agarose gel electrophoresis and visualized by ethidium bromide.
Transfection and small interfering RNA (siRNA)
MDA-MB-231 cells were seeded at a density of 1 × 105 cells/well in six-well culture plates the day before transfection to achieve 50-60% confluence. Wild-type p38 MAPK, a dominant negative (DN) p38 MAPK mutant or an empty vector were transfected into cells using Lipofectamine™ 2000 (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. The SMART pool siRNA against PKC δ used in this study was obtained from Dharmacon. Control siRNA-A, a negative control for experiments using targeted siRNA, was purchased from Santa Cruz Biotechnology (Santa Cruz, CA). Cells were transfected with siRNA oligonucleotides using Oligofectamine™ Reagent (Invitrogen).
reactive oxygen species
Abad MJ, Bessa AL, Ballarin B, Aragon O, Gonzales E, Bermejo P . Anti-inflammatory activity of four Bolivian Baccharis species (Compositae) . J Ethnopharmacol 2006 ; 103 : 338 - 344
Brown JR, DuBois RN . COX-2: a molecular target for colorectal cancer prevention . J Clin Oncol 2005 ; 23 : 2840 - 2855
Chandramohan G, Bai Y, Norris K, Rodriguez-Iturbe B, Vaziri ND . Effects of dietary salt on intrarenal angiotensin system, NAD(P)H oxidase, COX-2, MCP-1 and PAI-1 expressions and NF-kappaB activity in salt-sensitive and -resistant rat kidneys . Am J Nephrol 2008 ; 28 : 158 - 167
Chen WS, Wei SJ, Liu JM, Hsiao M, Kou-Lin J, Yang WK . Tumor invasiveness and liver metastasis of colon cancer cells correlated with cyclooxygenase-2 (COX-2) expression and inhibited by a COX-2-selective inhibitor, etodolac . Int J Cancer 2001 ; 91 : 894 - 899
Chiu WT, Shen SC, Chow JM, Lin CW, Shia LT, Chen YC . Contribution of reactive oxygen species to migration/invasion of human glioblastoma cells U87 via ERK-dependent COX-2/PGE(2) activation . Neurobiol Dis 2010 ; 37 : 118 - 129
Cross T, Griffiths G, Deacon E, Sallis R, Gough M, Watters D, Lord JM . PKC-delta is an apoptotic lamin kinase . Oncogene 2000 ; 19 : 2331 - 2337
Dannenberg AJ, Altorki NK, Boyle JO, Dang C, Howe LR, Weksler BB, Subbaramaiah K . Cyclo-oxygenase 2: a pharmacological target for the prevention of cancer . Lancet Oncol 2001 ; 2 : 544 - 551
Dean JL, Brook M, Clark AR, Saklatvala J . p38 mitogen-activated protein kinase regulates cyclooxygenase-2 mRNA stability and transcription in lipopolysaccharide-treated human monocytes . J Biol Chem 1999 ; 274 : 264 - 269
Dempke W, Rie C, Grothey A, Schmoll HJ . Cyclooxygenase-2: a novel target for cancer chemotherapy ? J Cancer Res Clin Oncol 2001 ; 127 : 411 - 417
Denkert C, Winzer KJ, Hauptmann S . Prognostic impact of cyclooxygenase-2 in breast cancer . Clin Breast Cancer 2004 ; 4 : 428 - 433
Di Mari JF, Saada JI, Mifflin RC, Valentich JD, Powell DW . HETEs enhance IL-1-mediated COX-2 expression via augmentation of message stability in human colonic myofibroblasts . Am J Physiol Gastrointest Liver Physiol 2007 ; 293 : G719 - G728
Feng L, Xia Y, Garcia GE, Hwang D, Wilson CB . Involvement of reactive oxygen intermediates in cyclooxygenase-2 expression induced by interleukin-1, tumor necrosis factor-alpha, and lipopolysaccharide . J Clin Invest 1995 ; 95 : 1669 - 1675
Griswold DE, Adams JL . Constitutive cyclooxygenase (COX-1) and inducible cyclooxygenase (COX-2): rationale for selective inhibition and progress to date . Med Res Rev 1996 ; 16 : 181 - 206
Gschwendt M, Muller HJ, Kielbassa K, Zang R, Kittstein W, Rincke G, Marks F . Rottlerin, a novel protein kinase inhibitor . Biochem Biophys Res Commun 1994 ; 199 : 93 - 98
Hsieh HL, Wang HH, Wu CY, Jou MJ, Yen MH, Parker P, Yang CM . BK-induced COX-2 expression via PKC-delta-dependent activation of p42/p44 MAPK and NF-kappaB in astrocytes . Cell Signal 2007 ; 19 : 330 - 340
Huang ZF, Massey JB, Via DP . Differential regulation of cyclooxygenase-2 (COX-2) mRNA stability by interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) in human in vitro differentiated macrophages . Biochem Pharmacol 2000 ; 59 : 187 - 194
Jaimes EA, Zhou MS, Pearse DD, Puzis L, Raij L . Upregulation of cortical COX-2 in salt-sensitive hypertension: role of angiotensin II and reactive oxygen species . Am J Physiol Renal Physiol 2008 ; 294 : F385 - F392
Jung YJ, Isaacs JS, Lee S, Trepel J, Neckers L . IL-1beta-mediated up-regulation of HIF-1alpha via an NFkappaB/COX-2 pathway identifies HIF-1 as a critical link between inflammation and oncogenesis . FASEB J 2003 ; 17 : 2115 - 2117
Kim SH, Oh JM, No JH, Bang YJ, Juhnn YS, Song YS . Involvement of NF-kappaB and AP-1 in COX-2 upregulation by human papillomavirus 16 E5 oncoprotein . Carcinogenesis 2009 ; 30 : 753 - 757
Kontny E, Kurowska M, Szczepanska K, Maslinski W . Rottlerin, a PKC isozyme-selective inhibitor, affects signaling events and cytokine production in human monocytes . J Leukoc Biol 2000 ; 67 : 249 - 258
Lasa M, Mahtani KR, Finch A, Brewer G, Saklatvala J, Clark AR . Regulation of cyclooxygenase 2 mRNA stability by the mitogen-activated protein kinase p38 signaling cascade . Mol Cell Biol 2000 ; 20 : 4265 - 4274
Lim JH, Park JW, Choi KS, Park YB, Kwon TK . Rottlerin induces apoptosis via death receptor 5 (DR5) upregulation through CHOP-dependent and PKC delta-independent mechanism in human malignant tumor cells . Carcinogenesis 2009 ; 30 : 729 - 736
Mifflin RC, Saada JI, Di Mari JF, Adegboyega PA, Valentich JD, Powell DW . Regulation of COX-2 expression in human intestinal myofibroblasts: mechanisms of IL-1-mediated induction . Am J Physiol Cell Physiol 2002 ; 282 : C824 - C834
Mifflin RC, Saada JI, Di Mari JF, Valentich JD, Adegboyega PA, Powell DW . Aspirin-mediated COX-2 transcript stabilization via sustained p38 activation in human intestinal myofibroblasts . Mol Pharmacol 2004 ; 65 : 470 - 478
Miralpeix M, Camacho M, Lopez-Belmonte J, Canalias F, Beleta J, Palacios JM, Vila L . Selective induction of cyclo-oxygenase-2 activity in the permanent human endothelial cell line HUV-EC-C: biochemical and pharmacological characterization . Br J Pharmacol 1997 ; 121 : 171 - 180
Mitchell JA, Belvisi MG, Akarasereenont P, Robbins RA, Kwon OJ, Croxtall J, Barnes PJ, Vane JR . Induction of cyclo-oxygenase-2 by cytokines in human pulmonary epithelial cells: regulation by dexamethasone . Br J Pharmacol 1994 ; 113 : 1008 - 1014
Molina-Holgado E, Ortiz S, Molina-Holgado F, Guaza C . Induction of COX-2 and PGE(2) biosynthesis by IL-1beta is mediated by PKC and mitogen-activated protein kinases in murine astrocytes . Br J Pharmacol 2000 ; 131 : 152 - 159
Nakao S, Ogtata Y, Shimizu E, Yamazaki M, Furuyama S, Sugiya H . Tumor necrosis factor alpha (TNF-alpha)-induced prostaglandin E2 release is mediated by the activation of cyclooxygenase-2 (COX-2) transcription via NFkappaB in human gingival fibroblasts . Mol Cell Biochem 2002 ; 238 : 11 - 18
Park EJ, Lim JH, Nam SI, Park JW, Kwon TK . Rottlerin induces heme oxygenase-1 (HO-1) up-regulation through reactive oxygen species (ROS) dependent and PKC delta-independent pathway in human colon cancer HT29 cells . Biochimie 2010 ; 92 : 110 - 115
Ridley SH, Dean JL, Sarsfield SJ, Brook M, Clark AR, Saklatvala J . A p38 MAP kinase inhibitor regulates stability of interleukin-1-induced cyclooxygenase-2 mRNA . FEBS Lett 1998 ; 439 : 75 - 80
Schieven GL . The biology of p38 kinase: a central role in inflammation . Curr Top Med Chem 2005 ; 5 : 921 - 928
Shishodia S, Koul D, Aggarwal BB . Cyclooxygenase (COX)-2 inhibitor celecoxib abrogates TNF-induced NF-kappa B activation through inhibition of activation of I kappa B alpha kinase and Akt in human non-small cell lung carcinoma: correlation with suppression of COX-2 synthesis . J Immunol 2004 ; 173 : 2011 - 2022
Smith WL, DeWitt DL, Garavito RM . Cyclooxygenases: structural, cellular, and molecular biology . Annu Rev Biochem 2000 ; 69 : 145 - 182
Soltoff SP . Rottlerin: an inappropriate and ineffective inhibitor of PKCdelta . Trends Pharmacol Sci 2007 ; 28 : 453 - 458
Song KS, Kim JS, Yun EJ, Kim YR, Seo KS, Park JH, Jung YJ, Park JI, Kweon GR, Yoon WH, Lim K, Hwang BD . Rottlerin induces autophagy and apoptotic cell death through a PKC-delta-independent pathway in HT1080 human fibrosarcoma cells: the protective role of autophagy in apoptosis . Autophagy 2008 ; 4 : 650 - 658
Song S, Guha S, Liu K, Buttar NS, Bresalier RS . COX-2 induction by unconjugated bile acids involves reactive oxygen species-mediated signalling pathways in Barrett's oesophagus and oesophageal adenocarcinoma . Gut 2007 ; 56 : 1512 - 1521
Tsatsanis C, Androulidaki A, Venihaki M, Margioris AN . Signalling networks regulating cyclooxygenase-2 . Int J Biochem Cell Biol 2006 ; 38 : 1654 - 1661
Woo KJ, Kwon TK . Sulforaphane suppresses lipopolysaccharide-induced cyclooxygenase-2 (COX-2) expression through the modulation of multiple targets in COX-2 gene promoter . Int Immunopharmacol 2007 ; 7 : 1776 - 1783
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Park, E., Kwon, T. Rottlerin enhances IL-1β-induced COX-2 expression through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells. Exp Mol Med 43, 669–675 (2011). https://doi.org/10.3858/emm.2011.43.12.077
- breast neoplasms
- p38 mitogen-activated protein kinases
- RNA stability
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