| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Experimental Therapeutics |
Departments of Epidemiology [M. A. M., M. S-A., M. L. F.] and Gastrointestinal Medical Oncology and Digestive Diseases [M. G. L., F. A. S.], The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
 |
ABSTRACT |
|---|
 Top ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
|
INTRODUCTION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
Recent studies have led to the recognition of the importance of COX-24
in colorectal tumorigenesis (3, 4, 5, 6, 7, 8)
. COX-2 has been shown to play a role in the development of intestinal neoplasms in genetically manipulated animal models (5)
. Specifically, the formation of intestinal polyps in Apc
716 knockout mice was dramatically suppressed by crossing these animals with COX-2 knockout mice (7)
. Up-regulation of COX-2 has been detected in human colorectal carcinomas relative to normal epithelium (3
, 4
, 9)
, and COX-2 expression has also been detected in gastric (10)
, esophageal (11
, 12)
, and lung (13
, 14)
carcinomas. COX enzymes catalyze the rate-limiting step in arachidonate metabolism, resulting in prostaglandin H2 production. This molecule is the precursor of other prostaglandins, prostacyclin, and thromboxanes. Two cyclooxygenase isoforms have been identified: COX-1 and COX-2 (15)
. COX-1 is expressed constitutively in several cell types in normal mammalian tissues, where it is involved in the maintenance of tissue homeostasis. In contrast, COX-2 is an inducible enzyme responsible for prostaglandin production at sites of inflammation (15
, 16)
. Growth factors, tumor promoters, cytokines, and other inflammatory mediators have been found to induce COX-2 expression (15
, 16)
. EGF is one of the growth factors known to up-regulate the expression of the COX-2 enzyme in several cell types such as human squamous carcinoma cells (17
, 18)
.
NSAIDs, including aspirin and sulindac, inhibit both COX-1 and COX-2 isoforms and have been shown to prevent colon cancer in animal models (8) . In a clinical trial, sulindac prevented new polyp formation and produced a significant regression of existing colorectal polyps in patients with familial adenomatous polyposis (19) . Furthermore, numerous epidemiological studies have shown that chronic NSAID usage is associated with a reduction in the incidence of colorectal cancer (8 , 20) . The NSAIDs indomethacin and phenylbutazone have also been shown to reduce the development of pancreatic cancer in a hamster model of this disease, in which tumors were initiated by treatment with N-nitrosobis(2-oxopropyl)amine (21) . Nonselective and selective COX-2 inhibitors have been shown to inhibit proliferation and to induce apoptosis of several cultured tumor cell lines, suggesting a mechanism for their antitumor effects (22, 23, 24, 25, 26) . The antiproliferative and chemopreventive properties of NSAIDs have been traditionally attributed to COX inhibition and a consequent reduction in prostaglandin levels. However, the sulfone metabolite of sulindac, which lacks COX-inhibitory activity, has been shown to have antiproliferative and proapoptotic properties and is an effective chemopreventive agent in an animal model of colon cancer (22 , 27) . Sulindac is a prodrug that is metabolized to its sulfide and sulfone derivatives (22) . The sulfide is a potent inhibitor of COX and is responsible for the anti-inflammatory effects of sulindac. NSAIDs can produce toxic effects, including gastrointestinal mucosal injury and renal dysfunction due to inhibition of COX-1. For this reason, a new class of NSAIDs that includes NS398 and SC58635 (Celecoxib) has recently been developed; these NSAIDs selectively inhibit the COX-2 isoform (24, 25, 26) . Available evidence suggests that these drugs retain the capacity to prevent experimental colorectal cancer (6) and are devoid of gastrointestinal mucosal toxicity, at least in short-term studies (28) .
To date, the expression of COX-2 in pancreatic cancer and the effects of NSAIDs on the growth of pancreatic carcinoma cell lines have not been analyzed. In this study, we report that human pancreatic tumors and cell lines express increased levels of COX-2 mRNA and protein and that both nonselective and selective COX-2 inhibitors reduce the growth of cultured pancreatic carcinoma cell lines.
|
MATERIALS AND METHODS |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
Cultured Tumor Cell Lines.
Pancreatic adenocarcinoma cell lines used in this study were Capan-1 (29)
and MDAPanc-3 (30)
, derived from liver metastases of well-differentiated and moderately differentiated tumors, respectively; BxPC-3, established from a moderately well-differentiated adenocarcinoma (31)
; MDAPanc-28, established from a poorly differentiated adenocarcinoma (32)
; and PANC-1, derived from a mostly undifferentiated carcinoma (33)
. HCA-7 colon cancer cells were obtained from Dr. S. Kirkland (Imperial Cancer Research Fund, London, United Kingdom). HCT-116 colon cancer cells and Capan-1, PANC-1, and BxPC-3 pancreatic cancer cell lines were obtained from the American Type Culture Collection (Manassas, VA). All cells were grown in DMEM/F-12 supplemented with 10% FBS, 2 mM glutamine, and 20 µg/ml gentamycin, unless otherwise indicated.
Immunohistochemistry.
Slides were deparaffinized, and endogenous peroxidase activity was blocked by incubation in 3% H2O2 in methanol for 10 min at room temperature. Sections were then microwaved in PBS for 4 min for antigen retrieval and incubated with avidin and then biotin (Vector Laboratories, Burlingame, CA) for 15 min each to block nonspecific binding. An immunoperoxidase technique was performed using the Vectastain ABC Elite kit (Vector Laboratories). A mouse monoclonal antibody against human COX-2 (Cayman Chemical Co., Ann Arbor, MI) was then applied at a dilution of 1:500 overnight at 4°C (9)
. This antibody recognizes a 19-amino acid sequence at the COOH terminus of COX-2 that is absent in COX-1. As a control for nonspecific staining, a COX-2 sequence-specific blocking peptide (Cayman Chemical) was used, which, when combined with the primary COX-2 antibody, completely suppressed COX-2 staining. Following rinsing with PBS, the biotinylated secondary IgG antibody was applied for 30 min at room temperature. Hematoxylin was used as a counterstain. As an additional negative control, the primary antibody was omitted. As a positive control, we used slides from a human colon carcinoma known to overexpress COX-2 proteins.
Neoplasms displaying COX-2 immunoreactivity in >5% of tumor cells were regarded as positive. Study specimens were evaluated independently by two examiners (M. A. M. and F. A. S.) and were reviewed by a pathologist.
Western Blot Assay.
Cells grown in 100-mm dishes in presence of DMEM/F-12 plus 10% FBS were washed twice with cold PBS, harvested in 0.5 ml of RIPA B lysis buffer [20 mM sodium phosphate (pH 7.4), 150 mM NaCl, 1% Triton X-100, 5 mM EDTA, 5 mM phenylmethylsulfonyl fluoride, 10 µg/ml aprotinin, 10 µg/ml leupeptin, and 250 µg/ml sodium vanadate] and lysed using a glass homogenizer. After removal of cell debris by centrifugation, the protein concentration in cell lysates was determined by the Bradford assay. Frozen tissue samples were homogenized in Tris-HCl buffer (pH 7.4) containing 0.5% NP40 and protease inhibitors (Boehringer Mannheim, Indianapolis, IN). Samples containing 150 µg of protein (for BxPC-3 and Capan-1 cells) or 300 µg (for MDAPanc-3, MDAPanc-28, and PANC-1 cells) were then added to SDS-PAGE loading buffer with 5% ß-mercaptoethanol, heated for 5 min at 100°C, and loaded in a 12% gel. For HCA-7 and HCT-116 colon cancer cell lines, blots were loaded with 100 µg of protein. Electrophoretic transfer to polyvinylidene difluoride membranes was followed by immunoblotting with the anti-COX-2 or anti-COX-1 antibodies (Cayman Chemical), a monoclonal antiactin antibody (Amersham, Arlington Heights, IL), and hybridization with a secondary antibody conjugated with peroxidase (Amersham). Signal was detected by chemiluminiscence using the ECL detection system (Amersham).
RNA Purification and RT-PCR.
RNA purification from human pancreatic tumors, paired normal tissues, and cell lines was performed by the acid guanidinium thiocyanate-phenol-chloroform method (34)
. The RNA was quantified by determining absorbance at 260 nm, and its quality assessed by subjecting it to electrophoresis in citric acid urea gels. Total RNA (1 µg) was converted to cDNA by incubation at 42°C for 1 h with 40 units of avian myeloblastosis virus reverse transcriptase in buffer I, 25 units of RNAse inhibitor, 0.4 mM dNTPs, and 100 ng of random primer p(dN)6. Final reaction volume was 20 µl. All reagents for cDNA synthesis were obtained from Boehringer Mannheim. The cDNA was then subjected to PCR. To obtain semiquantitative results, we optimized three parameters: cDNA concentration, number of cycles, and concentration of primers. The cDNA was diluted to 250 µl, and RT-PCR was performed using 15 µl of diluted cDNA (for COX-2) or 1 µl of a further 1:20 dilution of the already diluted cDNA (for ß-actin). In both cases, the reaction mixture contained 2 units of Taq polymerase Gold (Perkin Elmer/Applied Biosystems, Foster City, CA), 0.4 mM dNTPs, and 0.5 µg of the forward (F) and reverse (R) primers in a final volume of 50 µl. Amplification of COX-2 and ß-actin was performed at the same time so that the latter served as a control for efficiency of RT-PCR and amount of RNA. After a polymerase activation step (94°C for 12 min), samples were amplified for 35 cycles of denaturation at 94°C for 1 min, annealing at 54°C for 2 min, and extension at 72°C for 3 min, followed by an additional extension step (72°C for 5 min). The primer sequences and PCR product sizes were as follows: for COX-2, 5'-TTC AAA TGA GAT TGT GGG AAA AT-3' (F) and 5'-AGA TCA TCT CTG CCT GAG TAT CTT-3' (R), 304 bp; and for ß-actin, 5'-CGA GCG GGA AAT CGT GCG TGA CAT TAA GGA GA-3' (F) and 5'-CGT CAT ACT CCT GCT TGC TGA TCC ACA TCT GC-3' (R), 479 bp. The COX-2-specific primers possess <50% homology to the respective sites in the DNA sequence of COX-1 (35)
. Amplified cDNAs were run on 2% agarose gels with 0.5 µg/ml ethidium bromide, and visualized under UV light. RNAs from the colonic adenocarcinoma cell lines HCA-7 and HCT-116 were used as positive and negative controls, respectively.
Cell Proliferation Assay.
The effects of sulindac sulfide (Cell Pathways, Inc., Horsham, PA) and NS398 (Cayman Chemical) on cell growth were determined using a cell proliferation assay. Both drugs were dissolved in 100% DMSO as 1000x stock solutions and then diluted with DMEM/F-12 for cell culture experiments. The final concentration of DMSO for all treatments (including controls, where no drug was added) was maintained at 0.1%. All drug solutions were prepared fresh on the day of testing. Cells were seeded at a density of 5 x 103 per well for BxPC-3 and PANC-1, 2.5 x 103 per well for MDAPanc-3, or 2 x 103 per well for Capan-1 and MDAPanc-28, in 96-well plates in DMEM/F-12 containing 10% FBS. After 24 h, fresh medium was added containing sulindac sulfide or NS398 at concentrations of 0 to 200 µM. After a 4-day incubation, the MTS assay (Promega, Madison, WI) was performed to estimate the number of viable cells according to the manufacturer’s instructions. In the case of Capan-1 cells treated with NS398, the cell number was also estimated by direct cell counting after trypan blue staining due to a pronounced change in their cell morphology. The data were analyzed by the Student’s t test.
The effect of sulindac sulfide and NS398 upon the level of COX-2 expression was also studied. BxPC-3 cells, grown to 50% confluence in 100-mm dishes, were incubated in the presence of drug for 48 h in medium containing sulindac sulfide (75 µM) or NS398 (100 µM) or medium alone (control). COX-2 protein expression was then analyzed by the Western blot assay.
|
RESULTS AND DISCUSSION |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
. Pancreatic islets have been shown to constitutively express COX-2 (36)
. Expression of COX-2 protein was detected in 14 of 21 (67%) pancreatic adenocarcinomas analyzed. In these tumors, granular staining was seen in the cytoplasm of malignant cells (Fig. 1B and D–F)
. Lymphocytes and other interstitial mononuclear cells were consistently negative for COX-2. A COX-2 sequence-specific blocking peptide was used as a control for antibody specificity. In all cases analyzed, the peptide completely suppressed COX-2 staining (Fig. 1C)
.
|
. When compared to the healthy pancreas, the level of COX-2 transcript was elevated in all four carcinomas analyzed.
|
. The explanation for this observation is unclear, but it may be a consequence of tumor cell contamination or the induction of COX-2 expression in normal tissue by the adjacent tumor. Although COX-2 has not been detected in normal epithelial cells adjacent to colorectal (4
, 9)
or esophageal (11)
adenocarcinomas, we reported COX-2 staining in interstitial mononuclear cells adjacent to malignant glands in some colorectal cancers (9)
.
In separate experiments, we examined COX-2 and COX-1 protein expression in human colorectal carcinomas by Western blot analysis. Similar to results in pancreatic cancer, we found that COX-2 was up-regulated in colorectal cancers relative to normal epithelia from these same cases (Fig. 3
; Refs. 3
, 4
, and 9
). COX-1 was detected at an equivalent level in tumors and normal epithelia, consistent with its constitutive expression (4)
.
|
. Expression of COX-1 protein was detected only in BxPC-3 and Capan-1 cells (Fig. 4B)
. RT-PCR demonstrated that four of five pancreatic cancer cell lines expressed increased COX-2 mRNA levels when compared with normal pancreas from a healthy individual (Fig. 4B)
. BxPC-3 showed the highest level of mRNA expression, followed by Capan-1, MDAPanc-3, and MDAPanc-28. In the case of PANC-1 cells, the low level of COX-2 transcript was not increased over normal pancreas. The human colon cancer cell lines HCA-7, known to constitutively express high levels of COX-2 protein, and HCT-116, which lack COX-2 protein, were used as controls (24)
. COX-2 mRNA was detected in HCA-7 but not in HCT-116 cells (Fig. 4B)
. The high level of COX-2 mRNA detected in BxPC-3 cells was similar to that found in HCA-7 cells. Although not run on the same blot, the level of COX-2 protein in BxPC-3 cells approximated that found in HCA-7 colon cancer cells (Figs. 3
and 4A
). Taken together, our data indicate that COX-2 is up-regulated in pancreatic and colorectal cancer cell lines and human tumors. Findings in BxPC-3 and HCA-7 cell lines for both mRNA and protein suggest that similar levels of COX-2 expression may occur in these tumor types.
|
Effect of EGF on COX-2 Expression.
COX-2 is an intermediate-early response gene that has been shown to be regulated at the level of transcription (8
, 15)
. One growth factor known to induce COX-2 expression in certain cell types is EGF (17
, 18)
. Given the importance of the EGF/transforming growth factor-
signal transduction pathway in pancreatic cancer (38)
, we determined whether COX-2 can be induced by EGF in pancreatic cancer cell lines. BxPC-3 cells were grown in presence of 50 ng/ml EGF for 5 h, and COX-2 protein expression was then analyzed by Western blotting. EGF significantly induced COX-2 expression in serum-starved cells but not in the presence of serum (Fig. 5)
. The fact that a further induction of COX-2 by EGF did not occur in cells grown with 10% FBS suggests that growth factors present in serum may be sufficient to induce a high level of COX-2 expression. In this regard, the levels of COX-2 protein in cells grown in serum-free medium containing EGF and in FBS-supplemented medium were comparable. A similar induction of COX-2 expression by EGF was observed in serum-starved Capan-1 and MDAPanc-3 cells (data not shown). In these two cell lines and in BxPC-3 cells, COX-2 protein levels were very low but still detectable in cells growing in absence of serum and EGF. These results suggest a paracrine effect by exogenous growth factor on the induction of COX-2. Pancreatic tumor cell lines have also been shown to have an autocrine transforming growth factor-/EGF receptor loop that may contribute to COX-2 induction in absence of growth factors (38)
. In MDAPanc-28 and PANC-1 cells, EGF failed to induce COX-2 expression.
|
. IC50s for sulindac sulfide were: 
70 µM for BxPC-3 and Capan-1, 90 µM for PANC-1, 130 µM for MDAPanc-3, and 140 µM for MDAPanc-28 cells. The number of remaining viable cells at the highest concentrations of sulindac sulfide tested (160 and 200 µM) was markedly reduced compared to the initial cell number, suggesting that this drug may be inducing apoptosis. Studies in these cell lines are ongoing to verify induction of apoptosis; however, experiments in several colon carcinoma cell lines treated with sulindac sulfide and NS398 demonstrate a parallel inhibition of growth and induction of apoptosis (22
, 23
, 25
, 39)
. In these studies, evidence of apoptosis included characteristic morphology and DNA fragmentation and degradation. Finally, in the case of MDAPanc-28 cells, a change in morphology was observed at concentrations of the drugs exceeding 80 µM with cells becoming more elongated and enlarged.
|
NS398, a selective COX-2 inhibitor, also had growth-inhibitory effects on all pancreatic cancer cell lines tested (Fig. 6B)
. A similar effect has been reported in colon and prostate carcinoma cell lines, where NS398 was shown to inhibit proliferation and to induce apoptosis (25
, 26)
. Except in Capan-1 cells, the growth-inhibitory effects of NS398 were less pronounced than those produced by sulindac sulfide at the same concentrations. NS398 induced a change in cell morphology in all cell lines tested except BxPC-3. Cells became more elongated and enlarged and developed cytoplasmic projections, suggesting an effect of differentiation. These changes were very pronounced in Capan-1 cells. As with sulindac sulfide, no clear relationship was found between the level of COX-2 expression and the extent of growth inhibition by NS398, again suggesting that the effects of NSAIDs on pancreatic cancer cell growth could be mediated, at least in part, by a COX-2-independent pathway.
We also examined the effect of sulindac sulfide and NS398 on COX-2 protein expression by Western blot assay. We found that both drugs induced COX-2 expression in BxPC-3 cells and that the selective COX-2 inhibitor, NS398, produced a greater induction than did the nonselective drug (Fig. 7)
. This result is consistent with the data of Meade et al. (42)
, who showed that NSAIDs induced COX-2 expression in mammary epithelial cells and in colon carcinoma cell lines by increasing COX-2 transcription. Specifically, a region of the COX-2 promoter was identified that contains a peroxisome proliferator response element that appears to be responsible for COX-2 induction by these agents (42)
. Meade et al. (40)
found no effect of NSAIDs on the level of COX-1 expression. Greater induction of COX-2 by NS398 versus sulindac sulfide was also reported in the CaCo-2 colon cancer cell line (42)
. Because inhibition of COX-2 enzymatic activity is likely related to the antineoplastic effects of these drugs, the clinical significance of COX-2 protein induction by these agents is unclear.
|
3 x 106 cells). Furthermore, more sensitive methods such as RT-PCR can detect COX-2 expression in cell lines lacking detectable COX-2 protein levels, as shown for MDAPanc-28 and PANC-1 in this study. It is important to note that NSAID-induced growth inhibition and apoptosis in colon carcinoma cell lines was not reversed by addition of prostaglandin E2, the major COX product produced by colonic tumors (39
, 43)
. Chan et al. (43)
observed that sulindac sulfide and indomethacin treatment of colon carcinoma cells produced an elevation of arachidonic acid, the precursor of prostaglandins, which stimulated the conversion of sphingomyelin to ceramide, a potent inducer of apoptosis. These results suggest a COX-related mechanism for the chemopreventive efficacy of NSAIDs and support the ability of these compounds to reduce tumor formation in animal models systems. In conclusion, we have shown that COX-2 levels are frequently elevated in human pancreatic adenocarcinomas and cell lines derived from such tumors. In addition, EGF was found to induce COX-2 expression in several of these cell lines in the absence of serum. We demonstrate for the first time that nonselective (sulindac sulfide) and selective COX inhibitors (NS398) have antiproliferative effects on pancreatic cancer cells that were not predicted by the level of COX-2 expression. These drugs also induced the expression of their target enzyme, COX-2. The up-regulation of COX-2 in pancreatic cancers and the ability of NSAIDs to inhibit the growth of cell lines derived from these tumors is consistent with results in colon cancers and suggests that NSAIDs may also be effective chemopreventive agents in this malignancy.
|
ACKNOWLEDGMENTS |
|---|
|
FOOTNOTES |
|---|
1 Supported by NIH Grant CA 70759; NIH Cancer Center Support Grant CA 16672; and a Human Cancer Genetics grant (The University of Texas M. D. Anderson Cancer Center) and a Career Development Award from the American Cancer Society (both to F. A. S.). M. A. M. was supported by a Rotary Foundation Research Fellowship, and M. S-A. was a fellowship recipient from the Autonomous Government of Catalonia (Spain). 
2 These two authors contributed equally to this work.
3 To whom requests for reprints should be addressed, at Department of Gastrointestinal Medical Oncology and Digestive Diseases, Box 78, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030. Phone: (713) 792-2828; Fax: (713) 792-5010; E-mail: fsinicro{at}notes.mdacc.tmc.edu
4 The abbreviations used are: COX, cyclooxygenase; EGF, epidermal growth factor; NSAID, nonsteroidal anti-inflammatory drug; FBS, fetal bovine serum; RT-PCR, reverse transcription-PCR.
Received 4/ 6/99. Accepted 7/ 8/99.
|
REFERENCES |
|---|
|
TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
. Evidence for post-transcriptional regulation. J. Biol. Chem., 269: 11769-11775, 1994. in human pancreatic cells: evidence for a superagonist autocrine cycle. Proc. Natl. Acad. Sci. USA, 84: 7567-7570, 1987.This article has been cited by other articles:
|
|
 |
|
  A. E. Wallace, K. J. Sales, R. D. Catalano, R. A. Anderson, A. R.W. Williams, M. R. Wilson, J. Schwarze, H. Wang, A. G. Rossi, and H. N. Jabbour Prostaglandin F2{alpha}-F-Prostanoid Receptor Signaling Promotes Neutrophil Chemotaxis via Chemokine (C-X-C Motif) Ligand 1 in Endometrial Adenocarcinoma Cancer Res., July 15, 2009; 69(14): 5726 - 5733. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Danovi, H. H. Wong, and N. R. Lemoine Targeted therapies for pancreatic cancer Br. Med. Bull., September 1, 2008; 87(1): 97 - 130. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Dhillon, B. B. Aggarwal, R. A. Newman, R. A. Wolff, A. B. Kunnumakkara, J. L. Abbruzzese, C. S. Ng, V. Badmaev, and R. Kurzrock Phase II Trial of Curcumin in Patients with Advanced Pancreatic Cancer Clin. Cancer Res., July 15, 2008; 14(14): 4491 - 4499. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Adachi, Y. Tajima, T. Kuroki, T. Mishima, A. Kitasato, N. Tsuneoka, and T. Kanematsu Chemopreventive effects of a selective cyclooxygenase-2 inhibitor (etodolac) on chemically induced intraductal papillary carcinoma of the pancreas in hamsters Carcinogenesis, April 1, 2008; 29(4): 830 - 833. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. E. Hollingshead, M. G. Borland, A. N. Billin, T. M. Willson, F. J. Gonzalez, and J. M. Peters Ligand activation of peroxisome proliferator-activated receptor-{beta}/{delta} (PPAR{beta}/{delta}) and inhibition of cyclooxygenase 2 (COX2) attenuate colon carcinogenesis through independent signaling mechanisms Carcinogenesis, January 1, 2008; 29(1): 169 - 176. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Hazra, R. K. Batra, H. H. Tai, S. Sharma, X. Cui, and S. M. Dubinett Pioglitazone and Rosiglitazone Decrease Prostaglandin E2 in Non-Small-Cell Lung Cancer Cells by Up-Regulating 15-Hydroxyprostaglandin Dehydrogenase Mol. Pharmacol., June 1, 2007; 71(6): 1715 - 1720. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Soo, J Wu, A Aggarwal, Q Tao, W Hsieh, T Putti, K. Tan, W. Soon, Y. Lai, B Mow, et al. Celecoxib reduces microvessel density in patients treated with nasopharyngeal carcinoma and induces changes in gene expression Ann. Onc., November 1, 2006; 17(11): 1625 - 1630. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. P. Spugnini, I. Cardillo, A. Verdina, S. Crispi, S. Saviozzi, R. Calogero, A. Nebbioso, L. Altucci, G. Cortese, R. Galati, et al. Piroxicam and Cisplatin in a mouse model of peritoneal mesothelioma. Clin. Cancer Res., October 15, 2006; 12(20): 6133 - 6143. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Meng, S. Ceryak, Z. Aratsu, L. Jones, L. Epstein, and B. Bouscarel Biphasic regulation by bile acids of dermal fibroblast proliferation through regulation of cAMP production and COX-2 expression level Am J Physiol Cell Physiol, September 1, 2006; 291(3): C546 - C554. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Kern, A. M. Haugg, A. F. Koch, T. Schilling, K. Breuhahn, H. Walczak, B. Fleischer, C. Trautwein, C. Michalski, H. Schulze-Bergkamen, et al. Cyclooxygenase-2 Inhibition Induces Apoptosis Signaling via Death Receptors and Mitochondria in Hepatocellular Carcinoma. Cancer Res., July 15, 2006; 66(14): 7059 - 7066. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Abdelrahim, C. H. Baker, J. L. Abbruzzese, and S. Safe Tolfenamic acid and pancreatic cancer growth, angiogenesis, and Sp protein degradation. J Natl Cancer Inst, June 21, 2006; 98(12): 855 - 868. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Grosch, T. J. Maier, S. Schiffmann, and G. Geisslinger Cyclooxygenase-2 (COX-2)-independent anticarcinogenic effects of selective COX-2 inhibitors. J Natl Cancer Inst, June 7, 2006; 98(11): 736 - 747. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Siironen, A. Ristimaki, K. Narko, S. Nordling, J. Louhimo, S. Andersson, R. Haapiainen, and C. Haglund VEGF-C and COX-2 expression in papillary thyroid cancer. Endocr. Relat. Cancer, June 1, 2006; 13(2): 465 - 473. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Ouyang, J. L. Williams, G. J. Tsioulias, J. Gao, M. J. Iatropoulos, L. Kopelovich, K. Kashfi, and B. Rigas Nitric oxide-donating aspirin prevents pancreatic cancer in a hamster tumor model. Cancer Res., April 15, 2006; 66(8): 4503 - 4511. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A Juuti, J Louhimo, S Nordling, A Ristimaki, and C Haglund Cyclooxygenase-2 expression correlates with poor prognosis in pancreatic cancer J. Clin. Pathol., April 1, 2006; 59(4): 382 - 386. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Nunez, R. A. Valero, L. Senovilla, S. Sanz-Blasco, J. Garcia-Sancho, and C. Villalobos Cell proliferation depends on mitochondrial Ca2+ uptake: inhibition by salicylate J. Physiol., February 15, 2006; 571(1): 57 - 73. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Kaul, S. C. Verma, M. Murakami, K. Lan, T. Choudhuri, and E. S. Robertson Epstein-Barr Virus Protein Can Upregulate Cyclo-Oxygenase-2 Expression through Association with the Suppressor of Metastasis Nm23-H1 J. Virol., February 1, 2006; 80(3): 1321 - 1331. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Ali, B. F. El-Rayes, F. H. Sarkar, and P. A. Philip Simultaneous targeting of the epidermal growth factor receptor and cyclooxygenase-2 pathways for pancreatic cancer therapy Mol. Cancer Ther., December 1, 2005; 4(12): 1943 - 1951. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. F. Souza and S. J. Spechler Concepts in the Prevention of Adenocarcinoma of the Distal Esophagus and Proximal Stomach CA Cancer J Clin, November 1, 2005; 55(6): 334 - 351. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Symowicz, B. P. Adley, M. M.M. Woo, N. Auersperg, L. G. Hudson, and M. S. Stack Cyclooxygenase-2 Functions as a Downstream Mediator of Lysophosphatidic Acid to Promote Aggressive Behavior in Ovarian Carcinoma Cells Cancer Res., March 15, 2005; 65(6): 2234 - 2242. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Eibl, Y. Takata, L. G. Boros, J. Liu, Y. Okada, H. A. Reber, and O. J. Hines Growth Stimulation of COX-2-Negative Pancreatic Cancer by a Selective COX-2 Inhibitor Cancer Res., February 1, 2005; 65(3): 982 - 990. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Oida, B. Gopalan, R. Miyahara, S. Inoue, C. D. Branch, A. M. Mhashilkar, E. Lin, B. N. Bekele, J. A. Roth, S. Chada, et al. Sulindac enhances adenoviral vector expressing mda-7/IL-24-mediated apoptosis in human lung cancer Mol. Cancer Ther., February 1, 2005; 4(2): 291 - 304. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Gomez-Roman, P. Saenz, J. Cuevas Gonzalez, K. Escuredo, S. Santa Cruz, C. Junquera, L. Simon, A. Martinez, J. L. Gutierrez Banos, M. Lopez-Brea, et al. Fibroblast Growth Factor Receptor 3 Is Overexpressed in Urinary Tract Carcinomas and Modulates the Neoplastic Cell Growth Clin. Cancer Res., January 15, 2005; 11(2): 459 - 465. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. D. Basu, L. B. Pathangey, T. L. Tinder, M. LaGioia, S. J. Gendler, and P. Mukherjee Cyclooxygenase-2 Inhibitor Induces Apoptosis in Breast Cancer Cells in an In vivo Model of Spontaneous Metastatic Breast Cancer Mol. Cancer Res., November 1, 2004; 2(11): 632 - 642. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. F. El-Rayes, S. Ali, F. H. Sarkar, and P. A. Philip Cyclooxygenase-2-dependent and -independent effects of celecoxib in pancreatic cancer cell lines Mol. Cancer Ther., November 1, 2004; 3(11): 1421 - 1426. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Sato, N. Maehara, and M. Goggins Gene Expression Profiling of Tumor-Stromal Interactions between Pancreatic Cancer Cells and Stromal Fibroblasts Cancer Res., October 1, 2004; 64(19): 6950 - 6956. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. I. Abdalla, P. Lao-Sirieix, M. R. Novelli, L. B. Lovat, I. R. Sanderson, and R. C. Fitzgerald Gastrin-Induced Cyclooxygenase-2 Expression in Barrett's Carcinogenesis Clin. Cancer Res., July 15, 2004; 10(14): 4784 - 4792. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Kern, M. M. Schoneweiss, D. Sahi, M. Bahlo, A. M. Haugg, H. U. Kasper, H. P. Dienes, H. Kaferstein, K. Breuhahn, and P. Schirmacher Cyclooxygenase-2 inhibitors suppress the growth of human hepatocellular carcinoma implants in nude mice Carcinogenesis, July 1, 2004; 25(7): 1193 - 1199. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. A. Rich, R. C. Shepard, and S. T. Mosley Four Decades of Continuing Innovation With Fluorouracil: Current and Future Approaches to Fluorouracil Chemoradiation Therapy J. Clin. Oncol., June 1, 2004; 22(11): 2214 - 2232. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Quidville, N. Segond, E. Pidoux, R. Cohen, A. Jullienne, and S. Lausson Tumor Growth Inhibition by Indomethacin in a Mouse Model of Human Medullary Thyroid Cancer: Implication of Cyclooxygenases and 15-Hydroxyprostaglandin Dehydrogenase Endocrinology, May 1, 2004; 145(5): 2561 - 2571. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. N. Tucker, A. J. Dannenberg, E. K. Yang, and T. J. Fahey III Bile acids induce cyclooxygenase-2 expression in human pancreatic cancer cell lines Carcinogenesis, March 1, 2004; 25(3): 419 - 423. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. de Pascual-Teresa, K. L. Johnston, M. S. DuPont, K. A. O'Leary, P. W. Needs, L. M. Morgan, M. N. Clifford, Y. Bao, and G. Williamson Quercetin Metabolites Downregulate Cyclooxygenase-2 Transcription in Human Lymphocytes Ex Vivo but Not In Vivo J. Nutr., March 1, 2004; 134(3): 552 - 557. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. E. Kim, Y. B. Kim, N. H. Cho, H.-C. Chung, H. R. Pyo, J. D. Lee, T. K. Park, W. S. Koom, M. Chun, and C. O. Suh Synchronous Coexpression of Epidermal Growth Factor Receptor and Cyclooxygenase-2 in Carcinomas of the Uterine Cervix: A Potential Predictor of Poor Survival Clin. Cancer Res., February 15, 2004; 10(4): 1366 - 1374. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. S. Schernhammer, J.-H. Kang, A. T. Chan, D. S. Michaud, H. G. Skinner, E. Giovannucci, G. A. Colditz, and C. S. Fuchs A Prospective Study of Aspirin Use and the Risk of Pancreatic Cancer in Women J Natl Cancer Inst, January 7, 2004; 96(1): 22 - 28. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. G. Tessner, F. Muhale, S. Schloemann, S. M. Cohn, A. R. Morrison, and W. F. Stenson Ionizing radiation up-regulates cyclooxygenase-2 in I407 cells through p38 mitogen-activated protein kinase Carcinogenesis, January 1, 2004; 25(1): 37 - 45. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Sawaoka, D. A. Dixon, J. A. Oates, and O. Boutaud Tristetraprolin Binds to the 3'-Untranslated Region of Cyclooxygenase-2 mRNA. A POLYADENYLATION VARIANT IN A CANCER CELL LINE LACKS THE BINDING SITE J. Biol. Chem., April 11, 2003; 278(16): 13928 - 13935. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Chu, F. L. Lloyd, O. C. Trifan, B. Knapp, and M. T. Rizzo Potential Involvement of the Cyclooxygenase-2 Pathway in the Regulation of Tumor-associated Angiogenesis and Growth in Pancreatic Cancer Mol. Cancer Ther., January 1, 2003; 2(1): 1 - 7. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Dohadwala, R. K. Batra, J. Luo, Y. Lin, K. Krysan, M. Pold, S. Sharma, and S. M. Dubinett Autocrine/Paracrine Prostaglandin E2 Production by Non-small Cell Lung Cancer Cells Regulates Matrix Metalloproteinase-2 and CD44 in Cyclooxygenase-2-dependent Invasion J. Biol. Chem., December 20, 2002; 277(52): 50828 - 50833. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. J. Levitt and M. Pollak Insulin-like Growth Factor-I Antagonizes the Antiproliferative Effects of Cyclooxygenase-2 Inhibitors on BxPC-3 Pancreatic Cancer Cells Cancer Res., December 15, 2002; 62(24): 7372 - 7376. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Kashfi, Y. Ryann, L. L. Qiao, J. L. Williams, J. Chen, P. del Soldato, F. Traganos, and B. Rigas Nitric Oxide-Donating Nonsteroidal Anti-Inflammatory Drugs Inhibit the Growth of Various Cultured Human Cancer Cells: Evidence of a Tissue Type-Independent Effect J. Pharmacol. Exp. Ther., December 1, 2002; 303(3): 1273 - 1282. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-C. Huang, L.-Y. Chuang, and W.-C. Hung Mechanisms Underlying Nonsteroidal Anti-Inflammatory Drug-Induced p27Kip1 Expression Mol. Pharmacol., December 1, 2002; 62(6): 1515 - 1521. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Lim, H. Kim, and K. H. Kim Expression of Ku70 and Ku80 Mediated by NF-kappa B and Cyclooxygenase-2 Is Related to Proliferation of Human Gastric Cancer Cells J. Biol. Chem., November 22, 2002; 277(48): 46093 - 46100. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Sun, X. M. Tang, E. Half, M. T. Kuo, and F. A. Sinicrope Cyclooxygenase-2 Overexpression Reduces Apoptotic Susceptibility by Inhibiting the Cytochrome c-dependent Apoptotic Pathway in Human Colon Cancer Cells Cancer Res., November 1, 2002; 62(21): 6323 - 6328. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Tang, Y. J. Sun, E. Half, M. T. Kuo, and F. Sinicrope Cyclooxygenase-2 Overexpression Inhibits Death Receptor 5 Expression and Confers Resistance to Tumor Necrosis Factor-related Apoptosis-inducing Ligand-induced Apoptosis in Human Colon Cancer Cells Cancer Res., September 1, 2002; 62(17): 4903 - 4908. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. E. Anderson, T. W. Johnson, D. Lazovich, and A. R. Folsom Association Between Nonsteroidal Anti-Inflammatory Drug Use and the Incidence of Pancreatic Cancer J Natl Cancer Inst, August 7, 2002; 94(15): 1168 - 1171. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Hennig, X.-Z. Ding, W.-G. Tong, M. B. Schneider, J. Standop, H. Friess, M. W. Buchler, P. M. Pour, and T. E. Adrian 5-Lipoxygenase and Leukotriene B4 Receptor Are Expressed in Human Pancreatic Cancers But Not in Pancreatic Ducts in Normal Tissue Am. J. Pathol., August 1, 2002; 161(2): 421 - 428. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. R. Munkarah, R. Morris, P. Baumann, G. Deppe, J. Malone, M. P. Diamond, and G. M. Saed Effects of Prostaglandin E2 on Proliferation and Apoptosis of Epithelial Ovarian Cancer Cells Reproductive Sciences, May 1, 2002; 9(3): 168 - 173. [Abstract] [PDF]
|
|
|
|
|
|
M. J. Thun, S. J. Henley, and C. Patrono Nonsteroidal Anti-inflammatory Drugs as Anticancer Agents: Mechanistic, Pharmacologic, and Clinical Issues J Natl Cancer Inst, February 20, 2002; 94(4): 252 - 266. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. Wayne, E. K. Abdalla, R. A. Wolff, C. H. Crane, P. W.T. Pisters, and D. B. Evans Localized Adenocarcinoma of the Pancreas: The Rationale for Preoperative Chemoradiation Oncologist, February 1, 2002; 7(1): 34 - 45. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. D. Blumenthal, C. Waskewich, D. M. Goldenberg, W. Lew, C. Flefleh, and J. Burton Chronotherapy and Chronotoxicity of the Cyclooxygenase-2 Inhibitor, Celecoxib, in Athymic Mice Bearing Human Breast Cancer Xenografts Clin. Cancer Res., October 1, 2001; 7(10): 3178 - 3185. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. T. Yip-Schneider, C. J. Sweeney, S.-H. Jung, P. L. Crowell, and M. S. Marshall Cell Cycle Effects of Nonsteroidal Anti-Inflammatory Drugs and Enhanced Growth Inhibition in Combination with Gemcitabine in Pancreatic Carcinoma Cells J. Pharmacol. Exp. Ther., September 1, 2001; 298(3): 976 - 985. [Abstract] [Full Text]
|
|
|
|
 |
|
 K. M. Anderson and J. E. Harris Selected Features of Nonendocrine Pancreatic Cancer Experimental Biology and Medicine, June 1, 2001; 226(6): 521 - 537. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Shono, P. J. Tofilon, J. M. Bruner, O. Owolabi, and F. F. Lang Cyclooxygenase-2 Expression in Human Gliomas: Prognostic Significance and Molecular Correlations Cancer Res., June 1, 2001; 61(11): 4375 - 4381. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W.-C. Hung, H.-C. Chang, M.-R. Pan, T.-H. Lee, and L.-Y. Chuang Induction of p27KIP1 as a Mechanism Underlying NS398-Induced Growth Inhibition in Human Lung Cancer Cells Mol. Pharmacol., April 13, 2001; 58(6): 1398 - 1403. [Abstract] [Full Text]
|
|
|
|
|
|
M. Li, X. Wu, and X.-C. Xu Induction of Apoptosis in Colon Cancer Cells by Cyclooxygenase-2 Inhibitor NS398 through a Cytochrome c-dependent Pathway Clin. Cancer Res., April 1, 2001; 7(4): 1010 - 1016. [Abstract] [Full Text]
|
|
|
|
|
|
W. Motomura, T. Okumura, N. Takahashi, T. Obara, and Y. Kohgo Activation of Peroxisome Proliferator-activated Receptor {{gamma}} by Troglitazone Inhibits Cell Growth through the Increase of p27Kip1 in Human Pancreatic Carcinoma Cells Cancer Res., October 1, 2000; 60(19): 5558 - 5564. [Abstract] [Full Text]
|
|
|
|
|
|
R. F. Souza, K. Shewmake, D. G. Beer, B. Cryer, and S. J. Spechler Selective Inhibition of Cyclooxygenase-2 Suppresses Growth and Induces Apoptosis in Human Esophageal Adenocarcinoma Cells Cancer Res., October 1, 2000; 60(20): 5767 - 5772. [Abstract] [Full Text]
|
|
|
|
|
|
T. Joki, O. Heese, D. C. Nikas, L. Bello, J. Zhang, S.-K. Kraeft, N. T. Seyfried, T. Abe, L. B. Chen, R. S. Carroll, et al. Expression of Cyclooxygenase 2 (COX-2) in Human Glioma and in Vitro Inhibition by a Specific COX-2 Inhibitor, NS-398 Cancer Res., September 1, 2000; 60(17): 4926 - 4931. [Abstract] [Full Text]
|
|
|
|
|
|
H. Sasai, M. Masaki, and K. Wakitani Suppression of polypogenesis in a new mouse strain with a truncated Apc{Delta}474 by a novel COX-2 inhibitor, JTE-522 Carcinogenesis, May 1, 2000; 21(5): 953 - 958. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Rahman, D. K. Dhar, R. Masunaga, A. Yamanoi, H. Kohno, and N. Nagasue Sulindac and Exisulind Exhibit a Significant Antiproliferative Effect and Induce Apoptosis in Human Hepatocellular Carcinoma Cell Lines Cancer Res., April 1, 2000; 60(8): 2085 - 2089. [Abstract] [Full Text]
|
|
|
|
|
|
M. Dohadwala, J. Luo, L. Zhu, Y. Lin, G. J. Dougherty, S. Sharma, M. Huang, M. Pold, R. K. Batra, and S. M. Dubinett Non-small Cell Lung Cancer Cyclooxygenase-2-dependent Invasion Is Mediated by CD44 J. Biol. Chem., June 8, 2001; 276(24): 20809 - 20812. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
| Annual Meeting Education Book | Meeting Abstracts Online |
), Capan-1 (
), MDAPanc-3 (•), MDAPanc-28 (
), and PANC-1 (
). Cells growing in 96-well plates were treated with either drug for 4 days, and the MTS assay was performed to determine the number of viable cells as described in "Materials and Methods." Data points, means from six replicate wells; bars, SD. The effect of each treatment was calculated relative to vehicle (0.1% DMSO).