食管上皮细胞的COX-2表达、调控与细胞永生化及丝裂霉素C抗性
|
摘要
Ⅱ．1．1目的与方法
临床流行病学研究表明非甾体类抗炎药(NSAIDs)可以降低消化系肿瘤的发病率，其机制被认为与环氧合酶-2(COX-2)抑制有关。已发现COX-2在多种上皮性肿瘤内表达增加，但其在河南高发区食管癌组织的表达如何、受何种因素调节和控制、在食管上皮恶性转化过程中如何起作用、以及在肿瘤化疗中的意义如何，均尚未明了。本研究通过免疫组化检测，探讨食管癌组织COX-2表达与细胞分化及淋巴结转移的关系；结合原代细胞培养、Western Blotting和RT-PCR技术，分析血清对食管癌细胞株COX-2表达的影响，探讨TGF-β1与成纤维细胞的相互作用对COX-2表达的调控以及TGF-β受体在其中的地位；通过人乳头状瘤病毒-16-E_6E_7基因和端粒酶催化亚单位hTERT转染，建立食管上皮永生化模型，研究COX-2表达在此过程中的作用；配合流式细胞技术，探讨丝裂霉素C化疗对食管癌COX-2的表达及其影响。
Ⅱ．1．2主要结果与结论
Ⅱ．1．2．1食管癌组织中COX-2的表达及其意义
COX-2免疫阳性反应出现于51.6％(16／30)的食管癌组织，正常对照组织阴性；组织恶性分化程度与COX-2免疫反应的强度呈负相关(r=-0.564；P=0.001)；伴淋巴结转移者61.9％COX-2阳性(13／21)，但COX-2的免疫反应程度与淋巴结转移无关(K-S Z=0.830；P=0.496)，提示COX-2过度表达可能与食管癌细胞分化程度有关，可能成为食管癌防治，特别是高分化食管癌治疗的新靶点。
Ⅱ．1．2．2血清浓度对不同食管癌细胞株COX-2表达和细胞生长的影响
Western Blotting检测发现，TGF-βⅠ、Ⅱ受体在原代培养的正常食管上皮细
郑州大学博士学位论文2003届
胞和EC一18细胞中均有表达，ECa-109细胞只存在痕迹量的I型受体表达而n型
受体表达缺失。梯度浓度血清培养48小时后，在TGF一p受体功能缺失的ECa一109
细胞中，COX一2 n1RNA和蛋白质的表达均呈现浓度依赖性，而同时存在TGF-
pl、n受体表达的EC一18细胞，COX一2 mRNA和蛋白质的表达分别在血清10%
组和2.5%组出现高峰(P<0.05)，提示TGF一p;可能是血清中抑制cox一2表达的
因素，但MTT检测示食管癌细胞株ECa-109和EC一18均在O一10%的胎牛血清
浓度下表现出血清浓度依赖性生长趋势，提示COX-2表达水平的改变并非体外
培养条件下影响细胞增殖的决定性因素。对TGF一p受体表达形式不同的食管癌
细胞，不同血清浓度对COX一2表达影响不同，这一作用应列为体外培养条件下
肿瘤细胞COX一2研究不可忽视的重要影响因素之一。
n.1.2.3 TGF一pl与成纤维细胞的相互作用影响食管癌细胞COX-2表达
原代培养获得的成纤维细胞，一组加含10%FcS培养基、另一组另加5呵mL
的TGF一pl，分别培养24小时，收集上清，即为FS液及FSTB液。生长良好的
食管鳞癌细胞株EC卜109、EC一18分别设TGF一pl组、FS组和FSTB组，分别以
加入5呵mL TGF一pl的10%Fcs新鲜培养基、FS液及FsTB液完全换液，继续
培养24小时。结果发现，加入TGF一pl后，同时存在TGF一pl、n受体表达的
EC一18细胞中COX一2蛋白表达降至原来的0.103倍;加入FS液组上升2.368倍，
FSTB组上升2.793倍;TGF一pl组、FS组和FSTB组COX-2 mRNA表达量呈现
相同趋势(均尸<0.05)。在TGF一p受体功能缺陷的ECa一109细胞，TGF一p，组和
FS组cox-2蛋白的表达与10%FCs组无显著性差异护一0.87，尸一0.806)，而FSTB
组则明显升高2.292倍(P<0.05);COx-2 mRNA表达在TGF一p;组与10%FCS组
差别无显著性(P一0.903)，而FS组和FsTB组分别为10%FCS组的1.959倍和2.531
倍(均尸<0.05)。研究提示，TGF一pl可调节COX一2表达，且其作用受TGF一p受
体表达类型的影响，TGF一p;可使成纤维细胞产生刺激食管癌细胞COX一2表达
的物质，且至少在转录水平发挥作用。TGF一p;可以通过刺激成纤维细胞转而上
调COX一2表达，并可能因此影响食管癌的发生与发展。将COX-2表达用于食管
癌细胞分化与预后关系研究时，应考虑高分化癌组织中较多成纤维细胞的影响。
n.1.2.4食管上皮细胞的永生化与COX一2表达调控
原代培养获得纯化食管上皮细胞NEC凡，通过基因转染，获得表达hTERT
全文摘要
和/或1于V-16一E6E7的永生化食管上皮细胞。10%FCS存在条件下，NEC凡和食
管癌细胞均表达COX一2 mRNA与蛋白质，血清饥饿24hrs后，NEC凡细胞几乎
不能测得COX一2表达，食管癌细胞较含血清时表达稍弱，但仍明显强于NEC凡，
提示同等条件的血清刺激不会掩盖正常细胞与永生细胞间COX一2表达的差异;
在NEC凡、NEC凡一E6E:及NEC戊一E正7一hTERT细胞中，仅NEC凡一民 E7一hTERT
表达hTERT mRNA，提示HPv-16一氏E:转染可通过独立于端粒酶的方式引起
NEC凡细胞永生化;从NEC凡到NEC凡一E6E:再到NEC凡一E6E7一hTERT，COX一2
及Id一1蛋白的表达水平逐渐升高(P<0.05)，Cox一2与Id一1蛋白质水平的表达改
变相关(r一0.994，p一0.035)，mRNA水平也呈相应改变，但无统计学意义(P>0.05)，
提示转染HPV- 16一E6E:可上调食管上皮的COX一2表达，并因端粒酶活性的激活
进一步上升，食管上皮永生化过程中Id-1与COX一2表达的改变高度一致，提示
COX
11.2.1 Aims and methods
Esophageal carcinoma (EC) is one of the six most common malignancies in the world. Linzhou, formerly Linxian, and nearby county Huixian in Henan Province, China, is one of the highest incidence areas for EC. Etiology for EC is not clear. Second prevention is one of the very important strategies in reducing the incidence for EC, however, the progress in this area is not very promising. Recent studies have suggested that nonsteroid anti-inflammatory drugs could reduce the risk of gastric and colon cancer, presumably by inhibiting the COX enzyme. Cyclooxygenase includes two isoforms,known as cyclooxygenase-1 and cyclooxygenase-2 (COX-2),which
have different functions. Aberrant expression of COX-2 has been identified to increase cell proliferation and carcinogenesis. It has been documented that the expression of COX-2 is up-regulated in several epithelial tumor, but little is known about COX-2 for its expression in EC tissues in Henan high incidence area, the regulation factors, the effect on the esophageal epithelial ccarcinogenesis and the possible application in tumor chemotherapy. This study was designed to characterize COX-2 expression in EC tissues by immunohistochemical method and to correlate the alterations of COX-2 expression with EC cell differentiation and lymph node metastasis, to analysis the effect of serum concentrations on COX-2 expression in EC cell lines, to explore the function of TGF- β receptor and the interaction between TGF- β_(1) and fibroblast in regulation of COX-2 expression through primary cell culture, Western Blotting and RT-PCR technology, to establish immortalization cell models by HPV-16- E6E7 and hTERT transfecti
on and to determine the function of COX-2 expression in this process, and to investigate the function of COX-2 expression in EC cells after Mitomycin C treatment with flow cytometry.
II.2.2 Key results and conclusions
11.2.2.1 Increased expression of COX-2 protein in human EC
The positive immunostaining rate for COX-2 in 31 EC patients was 51.6% (16/31). No immunoreactivity was observed in control group. The differentiation progression of EC was inversely related to the expression of COX-2 (r=-0.564; P=0.001), but there was no correlation between metastasis characteristics of EC and intensity of COX-2 protein expression (Z=0.830;P=0.496). This study indicates that COX-2 protein over-expression may be one of the key molecular events correlated to the differentiation of EC, and it may shed new light on selecting molecular targets for EC prevention and treatment.
11.2.2.2 Effect of serum concentrations on COX-2 expression and cell growth in two EC cell lines.
Both the expressions of TGF- β RI and II were detected in primary cultured
normal esophageal epithelial cells and EC-18 cells, while only trace expressions of TGF- β receptor I and no TGF- β receptor II expression was found in ECa-109 cells. After 48hrs culture in gradient serum concentrations, including 10%, 5%, 2.5%, 1.25%, 0.625% and 0%, both the cell growth rates and COX-2 expression increased. ECa-109 cells, in which the functions of TGF- β receptor were lost, showed serum depended expression of COX-2 mRNA and protein, while EC-18 cells, in which the expression of TGF- β receptor I and II were active, showed peak COX-2 mRNA and protein expression in 10% and 2.5% PCS serum concentration groups (p<0.05). On the other hand, serum depended growth tendency was found in the two EC cell lines. These data implied that TGF- β_(1) should be at least one of the inhibitors for COX-2 expression in EC cells in vitro, while COX-2 may not be the key factor in cell proliferation control. Different serum concentrations had various effects on the expression of COX-2 in EC cells with different TG
F- β_(1) expression subtypes. The effect of serum concentration should not be ignored in the studies focusing on COX-2 expression and esophageal epithelial carcinogenesis in vitro.
II.2.2.3 Expression of COX-2 in EC cells was affected by the interaction between TGF- β_(1) a
临床流行病学研究表明非甾体类抗炎药(NSAIDs)可以降低消化系肿瘤的发病率，其机制被认为与环氧合酶-2(COX-2)抑制有关。已发现COX-2在多种上皮性肿瘤内表达增加，但其在河南高发区食管癌组织的表达如何、受何种因素调节和控制、在食管上皮恶性转化过程中如何起作用、以及在肿瘤化疗中的意义如何，均尚未明了。本研究通过免疫组化检测，探讨食管癌组织COX-2表达与细胞分化及淋巴结转移的关系；结合原代细胞培养、Western Blotting和RT-PCR技术，分析血清对食管癌细胞株COX-2表达的影响，探讨TGF-β1与成纤维细胞的相互作用对COX-2表达的调控以及TGF-β受体在其中的地位；通过人乳头状瘤病毒-16-E_6E_7基因和端粒酶催化亚单位hTERT转染，建立食管上皮永生化模型，研究COX-2表达在此过程中的作用；配合流式细胞技术，探讨丝裂霉素C化疗对食管癌COX-2的表达及其影响。
Ⅱ．1．2主要结果与结论
Ⅱ．1．2．1食管癌组织中COX-2的表达及其意义
COX-2免疫阳性反应出现于51.6％(16／30)的食管癌组织，正常对照组织阴性；组织恶性分化程度与COX-2免疫反应的强度呈负相关(r=-0.564；P=0.001)；伴淋巴结转移者61.9％COX-2阳性(13／21)，但COX-2的免疫反应程度与淋巴结转移无关(K-S Z=0.830；P=0.496)，提示COX-2过度表达可能与食管癌细胞分化程度有关，可能成为食管癌防治，特别是高分化食管癌治疗的新靶点。
Ⅱ．1．2．2血清浓度对不同食管癌细胞株COX-2表达和细胞生长的影响
Western Blotting检测发现，TGF-βⅠ、Ⅱ受体在原代培养的正常食管上皮细
郑州大学博士学位论文2003届
胞和EC一18细胞中均有表达，ECa-109细胞只存在痕迹量的I型受体表达而n型
受体表达缺失。梯度浓度血清培养48小时后，在TGF一p受体功能缺失的ECa一109
细胞中，COX一2 n1RNA和蛋白质的表达均呈现浓度依赖性，而同时存在TGF-
pl、n受体表达的EC一18细胞，COX一2 mRNA和蛋白质的表达分别在血清10%
组和2.5%组出现高峰(P<0.05)，提示TGF一p;可能是血清中抑制cox一2表达的
因素，但MTT检测示食管癌细胞株ECa-109和EC一18均在O一10%的胎牛血清
浓度下表现出血清浓度依赖性生长趋势，提示COX-2表达水平的改变并非体外
培养条件下影响细胞增殖的决定性因素。对TGF一p受体表达形式不同的食管癌
细胞，不同血清浓度对COX一2表达影响不同，这一作用应列为体外培养条件下
肿瘤细胞COX一2研究不可忽视的重要影响因素之一。
n.1.2.3 TGF一pl与成纤维细胞的相互作用影响食管癌细胞COX-2表达
原代培养获得的成纤维细胞，一组加含10%FcS培养基、另一组另加5呵mL
的TGF一pl，分别培养24小时，收集上清，即为FS液及FSTB液。生长良好的
食管鳞癌细胞株EC卜109、EC一18分别设TGF一pl组、FS组和FSTB组，分别以
加入5呵mL TGF一pl的10%Fcs新鲜培养基、FS液及FsTB液完全换液，继续
培养24小时。结果发现，加入TGF一pl后，同时存在TGF一pl、n受体表达的
EC一18细胞中COX一2蛋白表达降至原来的0.103倍;加入FS液组上升2.368倍，
FSTB组上升2.793倍;TGF一pl组、FS组和FSTB组COX-2 mRNA表达量呈现
相同趋势(均尸<0.05)。在TGF一p受体功能缺陷的ECa一109细胞，TGF一p，组和
FS组cox-2蛋白的表达与10%FCs组无显著性差异护一0.87，尸一0.806)，而FSTB
组则明显升高2.292倍(P<0.05);COx-2 mRNA表达在TGF一p;组与10%FCS组
差别无显著性(P一0.903)，而FS组和FsTB组分别为10%FCS组的1.959倍和2.531
倍(均尸<0.05)。研究提示，TGF一pl可调节COX一2表达，且其作用受TGF一p受
体表达类型的影响，TGF一p;可使成纤维细胞产生刺激食管癌细胞COX一2表达
的物质，且至少在转录水平发挥作用。TGF一p;可以通过刺激成纤维细胞转而上
调COX一2表达，并可能因此影响食管癌的发生与发展。将COX-2表达用于食管
癌细胞分化与预后关系研究时，应考虑高分化癌组织中较多成纤维细胞的影响。
n.1.2.4食管上皮细胞的永生化与COX一2表达调控
原代培养获得纯化食管上皮细胞NEC凡，通过基因转染，获得表达hTERT
全文摘要
和/或1于V-16一E6E7的永生化食管上皮细胞。10%FCS存在条件下，NEC凡和食
管癌细胞均表达COX一2 mRNA与蛋白质，血清饥饿24hrs后，NEC凡细胞几乎
不能测得COX一2表达，食管癌细胞较含血清时表达稍弱，但仍明显强于NEC凡，
提示同等条件的血清刺激不会掩盖正常细胞与永生细胞间COX一2表达的差异;
在NEC凡、NEC凡一E6E:及NEC戊一E正7一hTERT细胞中，仅NEC凡一民 E7一hTERT
表达hTERT mRNA，提示HPv-16一氏E:转染可通过独立于端粒酶的方式引起
NEC凡细胞永生化;从NEC凡到NEC凡一E6E:再到NEC凡一E6E7一hTERT，COX一2
及Id一1蛋白的表达水平逐渐升高(P<0.05)，Cox一2与Id一1蛋白质水平的表达改
变相关(r一0.994，p一0.035)，mRNA水平也呈相应改变，但无统计学意义(P>0.05)，
提示转染HPV- 16一E6E:可上调食管上皮的COX一2表达，并因端粒酶活性的激活
进一步上升，食管上皮永生化过程中Id-1与COX一2表达的改变高度一致，提示
COX
11.2.1 Aims and methods
Esophageal carcinoma (EC) is one of the six most common malignancies in the world. Linzhou, formerly Linxian, and nearby county Huixian in Henan Province, China, is one of the highest incidence areas for EC. Etiology for EC is not clear. Second prevention is one of the very important strategies in reducing the incidence for EC, however, the progress in this area is not very promising. Recent studies have suggested that nonsteroid anti-inflammatory drugs could reduce the risk of gastric and colon cancer, presumably by inhibiting the COX enzyme. Cyclooxygenase includes two isoforms,known as cyclooxygenase-1 and cyclooxygenase-2 (COX-2),which
have different functions. Aberrant expression of COX-2 has been identified to increase cell proliferation and carcinogenesis. It has been documented that the expression of COX-2 is up-regulated in several epithelial tumor, but little is known about COX-2 for its expression in EC tissues in Henan high incidence area, the regulation factors, the effect on the esophageal epithelial ccarcinogenesis and the possible application in tumor chemotherapy. This study was designed to characterize COX-2 expression in EC tissues by immunohistochemical method and to correlate the alterations of COX-2 expression with EC cell differentiation and lymph node metastasis, to analysis the effect of serum concentrations on COX-2 expression in EC cell lines, to explore the function of TGF- β receptor and the interaction between TGF- β_(1) and fibroblast in regulation of COX-2 expression through primary cell culture, Western Blotting and RT-PCR technology, to establish immortalization cell models by HPV-16- E6E7 and hTERT transfecti
on and to determine the function of COX-2 expression in this process, and to investigate the function of COX-2 expression in EC cells after Mitomycin C treatment with flow cytometry.
II.2.2 Key results and conclusions
11.2.2.1 Increased expression of COX-2 protein in human EC
The positive immunostaining rate for COX-2 in 31 EC patients was 51.6% (16/31). No immunoreactivity was observed in control group. The differentiation progression of EC was inversely related to the expression of COX-2 (r=-0.564; P=0.001), but there was no correlation between metastasis characteristics of EC and intensity of COX-2 protein expression (Z=0.830;P=0.496). This study indicates that COX-2 protein over-expression may be one of the key molecular events correlated to the differentiation of EC, and it may shed new light on selecting molecular targets for EC prevention and treatment.
11.2.2.2 Effect of serum concentrations on COX-2 expression and cell growth in two EC cell lines.
Both the expressions of TGF- β RI and II were detected in primary cultured
normal esophageal epithelial cells and EC-18 cells, while only trace expressions of TGF- β receptor I and no TGF- β receptor II expression was found in ECa-109 cells. After 48hrs culture in gradient serum concentrations, including 10%, 5%, 2.5%, 1.25%, 0.625% and 0%, both the cell growth rates and COX-2 expression increased. ECa-109 cells, in which the functions of TGF- β receptor were lost, showed serum depended expression of COX-2 mRNA and protein, while EC-18 cells, in which the expression of TGF- β receptor I and II were active, showed peak COX-2 mRNA and protein expression in 10% and 2.5% PCS serum concentration groups (p<0.05). On the other hand, serum depended growth tendency was found in the two EC cell lines. These data implied that TGF- β_(1) should be at least one of the inhibitors for COX-2 expression in EC cells in vitro, while COX-2 may not be the key factor in cell proliferation control. Different serum concentrations had various effects on the expression of COX-2 in EC cells with different TG
F- β_(1) expression subtypes. The effect of serum concentration should not be ignored in the studies focusing on COX-2 expression and esophageal epithelial carcinogenesis in vitro.
II.2.2.3 Expression of COX-2 in EC cells was affected by the interaction between TGF- β_(1) a
引文
1． Ballinger, A. and Smith, G. COX-2 inhibitors vs. NSAIDs in gastrointestinal damage and prevention. Expert.Opin.Pharmacother, 2: 31-40, 2001．
2． Castonguay, A., Rioux, N., Duperron, C., and Jalbert, G. Inhibition of lung tumorigenesis by NSAIDs: a working hypothesis. Exp.Lung Res., 24: 605-615, 1998．
3． Husain, S. S., Szabo, I. L., Pai, R., Soreghan, B., Jones, M. K., and Tarnawski, A. S. MAPK (ERK2) kinase--a key target for NSAIDs-induced inhibition of gastric cancer cell proliferation and growth. Life Sci., 69: 3045-3054, 2001．
4． Sawaoka, H., Kawano, S., Tsuji, S., Tsujii, M., Murata, H., and Hori, M. Effects of NSAIDs on proliferation of gastric cancer cells in vitro: possible implication of cyclooxygenase-2 in cancer development. J.Clin.Gastroenterol., 27 Suppl 1: S47-S52, 1998．
5． Bennett, A. and Del Tacca, M. Proceedings: Prostaglandins in human colonic carcinoma. Gut, 16: 409, 1975．
6． Kune, G. A., Kune, S., and Watson, L. F. Colorectal cancer risk, chronic illnesses, operations, and medications: case control results from the Melbourne Colorectal Cancer Study. Cancer Res., 48: 4399-4404, 1988．
7． Thun, M. J., Namboodiri, M. M., and Heath, C. W., Jr. Aspirin use and reduced risk of fatal colon cancer. N.Engl.J.Med., 325: 1593-1596, 1991．
8． Thun, M. J., Namboodiri, M. M., Calle, E. E., Flanders, W. D., and Heath, C. W., Jr. Aspirin use and risk of fatal cancer. Cancer Res., 53: 1322-1327, 1993．
9． Giovannucci, E., Egan, K. M., Hunter, D. J., Stampfer, M. J., Colditz, G. A., Willett, W. C., and Speizer, F. E. Aspirin and the risk of colorectal cancer in women. N.Engl.J.Med., 333: 609-614, 1995．
10． Lipton, A., Scialla, S., Harvey, H., Dixon, R., Gordon, R., Hamilton, R., Ramsey, H., Weltz, M., Heckard, R., and White, D. Adjuvant antiplatelet therapy with aspirin in colo-rectal cancer. J.Med., 13: 419-429, 1982．
11． Tanaka, T., Kohno, H., Shimada, R., Kagami, S., Yamaguchi, F., Kataoka, S., Ariga, T., Murakami, A., Koshimizu, K., and Ohigashi, H. Prevention of colonic aberrant crypt foci by dietary feeding of garcinol in male F344 rats. Carcinogenesis, 21: 1183-1189, 2000．
12． Schmid, K., Nair, J., Winde, G., Velic, I., and Bartsch, H. Increased levels of promutagenic etheno-DNA adducts in colonic polyps of FAP patients. Int.J.Cancer, 87: 1-4, 2000．
13． Oshima, M., Murai, N., Kargman, S., Arguello, M., Luk, P., Kwong, E., Taketo, M. M., and Evans, J. F. Chemoprevention of intestinal polyposis in the Apcdelta716 mouse by rofecoxib, a specific cyclooxygenase-2 inhibitor. Cancer Res., 61: 1733-1740, 2001．
14． Rubio, C. A. Antitumoral activity of indomethacin on experimental esophageal tumors. J.Natl.Cancer Inst, 72: 705-707, 1984．
15． Funkhouser, E. M. and Sharp, G. B. Aspirin and reduced risk of esophageal carcinoma. Cancer, 76: 1116-1119, 1995．
16． Antiplatelet Trialists' Collaboration. Collaborative overview of randomised trials of antiplatelet therapy-I: Prevention of death, myocardial infarction, and stroke
by prolonged antiplatelet therapy in various categories of patients. BMJ, 308: 81-106, 1994．
17． Ratnasinghe, D., Tangrea, J., Roth, M. J., Dawsey, S., Hu, N., Anver, M., Wang, Q. H., and Taylor, P. R. Expression of cyclooxygenase-2 in human squamous cell carcinoma of the esophagus; an immunohistochemical survey. Anticancer Res., 19: 171-174, 1999．
18． Zimmermann, K. C., Sarbia, M., Weber, A. A., Borchard, F., Gabbert, H. E., and Schror, K. Cyclooxygenase-2 expression in human esophageal carcinoma. Cancer Res., 59: 198-204, 1999．
19． Shamma, A., Yamamoto, H., Doki, Y., Okami, J., Kondo, M., Fujiwara, Y., Yano, M., Inoue, M., Matsuura, N., Shiozaki, H., and Monden, M. Up-regulation of cyclooxygenase-2 in squamous carcinogenesis of the esophagus. Clin.Cancer Res., 6: 1229-1238, 2000．
20． Biramijamal, F., Allameh, A., Mirbod, P., Groene, H. J., Koomagi, R., and Hollstein, M. Unusual profile and high prevalence of P53 mutations in esophageal squamous cell carcinomas from northern Iran. Cancer Res., 61: 3119-3123,2001．
21． Li, Z., Shimada, Y., Kawabe, A., Sato, F., Maeda, M., Komoto, I., Hong, T., Ding, Y., Kaganoi, J., and Imamura, M. Suppression of N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis in F344 rats by JTE-522, a selective COX-2 inhibitor. Carcinogenesis, 22: 547-551, 2001．
22． Song, S. and Xu, X. C. Effect of benzo[a]pyrene diol epoxide on expression of retinoic acid receptor-beta in immortalized esophageal epithelial cells and esophageal cancer cells. Biochem.Biophys.Res.Commun., 257: 872-877, 2001．
23． Paganini-Hill, A., Chao, A., Ross, R. K., and Henderson, B. E. Aspirin use and chronic diseases: a cohort study of the elderly. BMJ, 299: 1247-1250, 1989．
24． Rosenberg, L., Palmer, J. R., Zauber, A. G., Warshauer, M. E., Stolley, P. D., and Shapiro, S. A hypothesis: nonsteroidal anti-inflammatory drugs reduce the incidence of large-bowel cancer. J.Natl.Cancer Inst., 83: 355-358, 1991．
25． Shirvani, V. N., Ouatu-Lascar, R., Kaur, B. S., Omary, M. B., and Triadafilopoulos, G. Cyclooxygenase 2 expression in Barrett's esophagus and adenocarcinoma: Ex vivo induction by bile salts and acid exposure. Gastroenterology, 118: 487-496, 2000．
26． Suh, O., Mettlin, C., and Petrelli, N. J. Aspirin use, cancer, and polyps of the large bowel. Cancer, 72: 1171-1177, 1993．
27． Gridley, G., McLaughlin, J. K., Ekbom, A., Klareskog, L., Adami, H. O., Hacker, D. G., Hoover, R., and Fraumeni, J. F., Jr. Incidence of cancer among patients with rheumatoid arthritis. J.Natl.Cancer Inst, 85: 307-311, 1993．
28． Yamamoto, H., Itoh, F., Fukushima, H., Hinoda, Y., and Imai, K. Overexpression of cyclooxygenase-2 protein is less frequent in gastric cancers with microsatellite instability. Int.J.Cancer, 84; 400-403, 1999．
29． Konturek, P. C., Hartwich, A., Zuchowicz, M., Labza, H., Pierzchalski, P., Karczewska, E., Bielanski, W., Hahn, E. G., and Konturek, S. J. Helicobacter pylori, gastrin and cyclooxygenases in gastric cancer. J.Physiol Pharmacol., 57: 737-749, 2000．
30． Konturek, S. J., Konturek, P. C., Hartwich, A., and Hahn, E. G. Helicobacter pylori infection and gastrin and Cyclooxygenase expression in gastric and colorectal malignancies. Regul.Pept., 93: 13-19, 2000．
31． Murata, H., Kawano, S., Tsuji, S., Tsuji, M., Sawaoka, H., Kimura, Y., Shiozaki, H., and Hori, M. Cyclooxygenase-2 Overexpression enhances lymphatic invasion and metastasis in human gastric carcinoma. Am.J.Gastroenterol., 94: 451-455, 1999．
32． Uefuji, K., Ichikura, T., and Mochizuki, H. Expression of cyclooxygenase-2 in human gastric adenomas and adenocarcinomas. J.Surg.Oncol., 76: 26-30, 2001．
33． Uefuji, K., Ichikura, T., and Mochizuki, H. Cyclooxygenase-2 expression is related to prostaglandin biosynthesis and angiogenesis in human gastric cancer. Clin.Cancer Res., 6: 135-138, 2000．
34． Akhtar, M., Cheng, Y., Magno, R. M., Ashktorab, H., Smoot, D. T., Meltzer, S. J., and Wilson, K. T. Promoter methylation regulates Helicobacter
pylori-stimulated cyclooxygenase-2 expression in gastric epithelial cells. Cancer Res., 67:2399-2403, 2001．
35． Sjodahl, R. Nonsteroidal anti-inflammatory drugs and the gastrointestinal tract. Extent, mode, and dose dependence of anticancer effects. Am.J.Med., 110． 668-698,2001．
36． DuBois, R. N., Radhika, A., Reddy, B. S., and Entingh, A. J. Increased cyclooxygenase-2 levels in carcinogen-induced rat colonic tumors. Gastroenterology, 110: 1259-1262, 1996．
37． Oshima, M., Dinchuk, J. E., Kargman, S. L., Oshima, H., Hancock, B., Kwong, E., Trzaskos, J. M., Evans, J. F., and Taketo, M. M. Suppression of intestinal polyposis in Apc delta716 knockout mice by inhibition of cyclooxygenase 2 (COX-2) . Cell, 87: 803-809, 1996．
38． Reddy, B. S., Rao, C. V., and Seibert, K. Evaluation of cyclooxygenase-2 inhibitor for potential chemopreventive properties in colon carcinogenesis. Cancer Res., 56: 4566-4569, 1996．
39． Takahashi, M., Fukutake, M., Yokota, S., Ishida, K., Wakabayashi, K., and Sugimura, T. Suppression of azoxymethane-induced aberrant crypt foci in rat colon by nimesulide, a selective inhibitor of cyclooxygenase 2． J. Cancer Res.Clin.Oncol.,122: 219-222, 1996．
40． DuBois, R. N., Shao, J., Tsujii, M., Sheng, H., and Beauchamp, R. D. G1 delay in cells overexpressing prostaglandin endoperoxide synthase-2． Cancer Res., 56: 733-737, 1996．
41． Marnett, L. J. Generation of mutagens during arachidonic acid metabolism. Cancer Metastasis Rev., 73: 303-308, 1994．
42． Tortora, G., Caputo, R., Damiano, V., Melisi, D., Bianco, R., Fontanini, G, Veneziani, B. M., De Placido, S., Bianco, A. R., and Ciardiello, F. Combination of a Selective Cyclooxygenase-2 Inhibitor with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor ZD1839 and Protein Kinase A Antisense Causes Cooperative Antitumor and Antiangiogenic Effect. Clin.Cancer Res., 9: 1566-1572, 2003．
43． Kirkpatrick, K., Ogunkolade, W., Elkak, A., Bustin, S., Jenkins, P., Ghilchik, M., and Mokbel, K. The mRNA expression of cyclo-oxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in human breast cancer. Curr.Med.Res.Opin., 18: 237-241, 2002．
44． Yamauchi, T., Watanabe, M., Hasegawa, H., Nishibori, H., Ishii, Y., Tatematsu, H., Yamamoto, K., Kubota, T., and Kitajima, M. The potential for a selective cyclooxygenase-2 inhibitor in the prevention of liver metastasis in human colorectal cancer. Anticancer Res., 23: 245-249, 2003．
45． Heslin, M. J., Yan, I, Johnson, M. R., Weiss, H., Diasio, R. B., and Urist, M. M. Role of matrix metalloproteinases in colorectal carcinogenesis. Ann.Surg., 233: 786-792,2001．
46． Nagatsuka, I., Yamada, N., Shimizu, S., Ohira, M., Nishino, H., Seki, S., and Hirakawa, K. Inhibitory effect of a selective cyclooxygenase-2 inhibitor on liver metastasis of colon cancer. Int. J.Cancer, 100: 515-519, 2002．
47． Vadlamudi, R., Mandal, M., Adam, L., Steinbach, G., Mendelsohn, J., and Kumar, R. Regulation of cyclooxygenase-2 pathway by HER2 receptor. Oncogene, 18: 305-314, 1999．
48． Hong, S. H., Avis, I., Vos, M. D., Martinez, A., Treston, A. M., and Mulshine, J. L. Relationship of arachidonic acid metabolizing enzyme expression in epithelial cancer cell lines to the growth effect of selective biochemical inhibitors. Cancer Res., 59: 2223-2228, 1999．
49． Lipsky, P. E. The clinical potential of cyclooxygenase-2-specific inhibitors. Am.J.Med., 106: 51S-57S, 1999．
50． Ryan, A. R., Rosita, A. R., Kamarul, A. K., and Qureshi, A. COX-2 inhibitors: a potential target for drug therapy in the management of colorectal cancer. Med.J.Malaysia, 54: 293-295, 1999．
51． Boudreau, M. D., Sohn, K. H., Rhee, S. H., Lee, S. W., Hunt, J. D., and Hwang, D. H. Suppression of tumor cell growth both in nude mice and in culture by n-3 polyunsaturated fatty acids, mediation through cyclooxygenase-independent pathways. Cancer Res., 61: 1386-1391, 2001．
52． Taylor, M. T., Lawson, K. R, Ignatenko, N. A., Marek, S. E., Stringer, D. E., Skovan, B. A., and Gerner, E. W. Sulindac sulfone inhibits K-ras-dependent cyclooxygenase-2 expression in human colon cancer cells. Cancer Res., 60: 6607-6610, 2000．
53． Kojima, M., Morisaki, T., Izuhara, K., Uchiyama, A., Matsunari, Y., Katano, M., and Tanaka, M. Lipopolysaccharide increases cyclo-oxygenase-2 expression in a colon carcinoma cell line through nuclear factor-kappa B activation. Oncogene, 19． 1225-1231,2000．
54． Fosslien, E. Molecular pathology of cyclooxygenase-2 in neoplasia. Ann.Clin.Lab Sci., 30: 3-21, 2000．
55． Stark L.A., Loveridge C.J., and Dunlop M.G. Interaction between beta-catenin and NF-kappa B-a possible mechanism for aspirin-induced repression of NF-kappa B activity and apoptosis in colorectal cancer cells. Proceedings of the American Association for Cancer Research 94th annual Meeting, 44: 4249, 2003
56． Ding H., Gibson-D'Ambrosio R. E., Han C., and D'Ambrosio S. M. Piroxicam selectively targets human premalignant and malignant oral cells via COX dependent and independent pathways. Proceedings of the American Association for Cancer Research 94th annual Meeting, 44: 4915, 2003
57． Yip-Schneider M. T., Sweeney C. J., Nakshatri H., Marshall M. S., and Schmidt C. M. Nuclear factor-kappa B inhibition augments growth suppression by sulindac in pancreatic cancer cells. Proceedings of the American Association for Cancer Research 94th annual Meeting, 44: 6365, 2003
58． Sinicrope, F. A, Lemoine, M., Xi, L., Lynch, P. M., Cleary, K. R., Shen, Y., and Frazier, M. L. Reduced expression of cyclooxygenase 2 proteins in hereditary nonpolyposis colorectal cancers relative to sporadic cancers. Gastroenterology, 117: 350-358, 1999．
59． Toyota, M., Shen, L., Ohe-Toyota, M., Hamilton, S. R., Sinicrope, F. A., and Issa, J. P. Aberrant methylation of the Cyclooxygenase 2 CpG island in colorectal tumors. Cancer Res., 60: 4044-4048, 2000．
2． Castonguay, A., Rioux, N., Duperron, C., and Jalbert, G. Inhibition of lung tumorigenesis by NSAIDs: a working hypothesis. Exp.Lung Res., 24: 605-615, 1998．
3． Husain, S. S., Szabo, I. L., Pai, R., Soreghan, B., Jones, M. K., and Tarnawski, A. S. MAPK (ERK2) kinase--a key target for NSAIDs-induced inhibition of gastric cancer cell proliferation and growth. Life Sci., 69: 3045-3054, 2001．
4． Sawaoka, H., Kawano, S., Tsuji, S., Tsujii, M., Murata, H., and Hori, M. Effects of NSAIDs on proliferation of gastric cancer cells in vitro: possible implication of cyclooxygenase-2 in cancer development. J.Clin.Gastroenterol., 27 Suppl 1: S47-S52, 1998．
5． Bennett, A. and Del Tacca, M. Proceedings: Prostaglandins in human colonic carcinoma. Gut, 16: 409, 1975．
6． Kune, G. A., Kune, S., and Watson, L. F. Colorectal cancer risk, chronic illnesses, operations, and medications: case control results from the Melbourne Colorectal Cancer Study. Cancer Res., 48: 4399-4404, 1988．
7． Thun, M. J., Namboodiri, M. M., and Heath, C. W., Jr. Aspirin use and reduced risk of fatal colon cancer. N.Engl.J.Med., 325: 1593-1596, 1991．
8． Thun, M. J., Namboodiri, M. M., Calle, E. E., Flanders, W. D., and Heath, C. W., Jr. Aspirin use and risk of fatal cancer. Cancer Res., 53: 1322-1327, 1993．
9． Giovannucci, E., Egan, K. M., Hunter, D. J., Stampfer, M. J., Colditz, G. A., Willett, W. C., and Speizer, F. E. Aspirin and the risk of colorectal cancer in women. N.Engl.J.Med., 333: 609-614, 1995．
10． Lipton, A., Scialla, S., Harvey, H., Dixon, R., Gordon, R., Hamilton, R., Ramsey, H., Weltz, M., Heckard, R., and White, D. Adjuvant antiplatelet therapy with aspirin in colo-rectal cancer. J.Med., 13: 419-429, 1982．
11． Tanaka, T., Kohno, H., Shimada, R., Kagami, S., Yamaguchi, F., Kataoka, S., Ariga, T., Murakami, A., Koshimizu, K., and Ohigashi, H. Prevention of colonic aberrant crypt foci by dietary feeding of garcinol in male F344 rats. Carcinogenesis, 21: 1183-1189, 2000．
12． Schmid, K., Nair, J., Winde, G., Velic, I., and Bartsch, H. Increased levels of promutagenic etheno-DNA adducts in colonic polyps of FAP patients. Int.J.Cancer, 87: 1-4, 2000．
13． Oshima, M., Murai, N., Kargman, S., Arguello, M., Luk, P., Kwong, E., Taketo, M. M., and Evans, J. F. Chemoprevention of intestinal polyposis in the Apcdelta716 mouse by rofecoxib, a specific cyclooxygenase-2 inhibitor. Cancer Res., 61: 1733-1740, 2001．
14． Rubio, C. A. Antitumoral activity of indomethacin on experimental esophageal tumors. J.Natl.Cancer Inst, 72: 705-707, 1984．
15． Funkhouser, E. M. and Sharp, G. B. Aspirin and reduced risk of esophageal carcinoma. Cancer, 76: 1116-1119, 1995．
16． Antiplatelet Trialists' Collaboration. Collaborative overview of randomised trials of antiplatelet therapy-I: Prevention of death, myocardial infarction, and stroke
by prolonged antiplatelet therapy in various categories of patients. BMJ, 308: 81-106, 1994．
17． Ratnasinghe, D., Tangrea, J., Roth, M. J., Dawsey, S., Hu, N., Anver, M., Wang, Q. H., and Taylor, P. R. Expression of cyclooxygenase-2 in human squamous cell carcinoma of the esophagus; an immunohistochemical survey. Anticancer Res., 19: 171-174, 1999．
18． Zimmermann, K. C., Sarbia, M., Weber, A. A., Borchard, F., Gabbert, H. E., and Schror, K. Cyclooxygenase-2 expression in human esophageal carcinoma. Cancer Res., 59: 198-204, 1999．
19． Shamma, A., Yamamoto, H., Doki, Y., Okami, J., Kondo, M., Fujiwara, Y., Yano, M., Inoue, M., Matsuura, N., Shiozaki, H., and Monden, M. Up-regulation of cyclooxygenase-2 in squamous carcinogenesis of the esophagus. Clin.Cancer Res., 6: 1229-1238, 2000．
20． Biramijamal, F., Allameh, A., Mirbod, P., Groene, H. J., Koomagi, R., and Hollstein, M. Unusual profile and high prevalence of P53 mutations in esophageal squamous cell carcinomas from northern Iran. Cancer Res., 61: 3119-3123,2001．
21． Li, Z., Shimada, Y., Kawabe, A., Sato, F., Maeda, M., Komoto, I., Hong, T., Ding, Y., Kaganoi, J., and Imamura, M. Suppression of N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis in F344 rats by JTE-522, a selective COX-2 inhibitor. Carcinogenesis, 22: 547-551, 2001．
22． Song, S. and Xu, X. C. Effect of benzo[a]pyrene diol epoxide on expression of retinoic acid receptor-beta in immortalized esophageal epithelial cells and esophageal cancer cells. Biochem.Biophys.Res.Commun., 257: 872-877, 2001．
23． Paganini-Hill, A., Chao, A., Ross, R. K., and Henderson, B. E. Aspirin use and chronic diseases: a cohort study of the elderly. BMJ, 299: 1247-1250, 1989．
24． Rosenberg, L., Palmer, J. R., Zauber, A. G., Warshauer, M. E., Stolley, P. D., and Shapiro, S. A hypothesis: nonsteroidal anti-inflammatory drugs reduce the incidence of large-bowel cancer. J.Natl.Cancer Inst., 83: 355-358, 1991．
25． Shirvani, V. N., Ouatu-Lascar, R., Kaur, B. S., Omary, M. B., and Triadafilopoulos, G. Cyclooxygenase 2 expression in Barrett's esophagus and adenocarcinoma: Ex vivo induction by bile salts and acid exposure. Gastroenterology, 118: 487-496, 2000．
26． Suh, O., Mettlin, C., and Petrelli, N. J. Aspirin use, cancer, and polyps of the large bowel. Cancer, 72: 1171-1177, 1993．
27． Gridley, G., McLaughlin, J. K., Ekbom, A., Klareskog, L., Adami, H. O., Hacker, D. G., Hoover, R., and Fraumeni, J. F., Jr. Incidence of cancer among patients with rheumatoid arthritis. J.Natl.Cancer Inst, 85: 307-311, 1993．
28． Yamamoto, H., Itoh, F., Fukushima, H., Hinoda, Y., and Imai, K. Overexpression of cyclooxygenase-2 protein is less frequent in gastric cancers with microsatellite instability. Int.J.Cancer, 84; 400-403, 1999．
29． Konturek, P. C., Hartwich, A., Zuchowicz, M., Labza, H., Pierzchalski, P., Karczewska, E., Bielanski, W., Hahn, E. G., and Konturek, S. J. Helicobacter pylori, gastrin and cyclooxygenases in gastric cancer. J.Physiol Pharmacol., 57: 737-749, 2000．
30． Konturek, S. J., Konturek, P. C., Hartwich, A., and Hahn, E. G. Helicobacter pylori infection and gastrin and Cyclooxygenase expression in gastric and colorectal malignancies. Regul.Pept., 93: 13-19, 2000．
31． Murata, H., Kawano, S., Tsuji, S., Tsuji, M., Sawaoka, H., Kimura, Y., Shiozaki, H., and Hori, M. Cyclooxygenase-2 Overexpression enhances lymphatic invasion and metastasis in human gastric carcinoma. Am.J.Gastroenterol., 94: 451-455, 1999．
32． Uefuji, K., Ichikura, T., and Mochizuki, H. Expression of cyclooxygenase-2 in human gastric adenomas and adenocarcinomas. J.Surg.Oncol., 76: 26-30, 2001．
33． Uefuji, K., Ichikura, T., and Mochizuki, H. Cyclooxygenase-2 expression is related to prostaglandin biosynthesis and angiogenesis in human gastric cancer. Clin.Cancer Res., 6: 135-138, 2000．
34． Akhtar, M., Cheng, Y., Magno, R. M., Ashktorab, H., Smoot, D. T., Meltzer, S. J., and Wilson, K. T. Promoter methylation regulates Helicobacter
pylori-stimulated cyclooxygenase-2 expression in gastric epithelial cells. Cancer Res., 67:2399-2403, 2001．
35． Sjodahl, R. Nonsteroidal anti-inflammatory drugs and the gastrointestinal tract. Extent, mode, and dose dependence of anticancer effects. Am.J.Med., 110． 668-698,2001．
36． DuBois, R. N., Radhika, A., Reddy, B. S., and Entingh, A. J. Increased cyclooxygenase-2 levels in carcinogen-induced rat colonic tumors. Gastroenterology, 110: 1259-1262, 1996．
37． Oshima, M., Dinchuk, J. E., Kargman, S. L., Oshima, H., Hancock, B., Kwong, E., Trzaskos, J. M., Evans, J. F., and Taketo, M. M. Suppression of intestinal polyposis in Apc delta716 knockout mice by inhibition of cyclooxygenase 2 (COX-2) . Cell, 87: 803-809, 1996．
38． Reddy, B. S., Rao, C. V., and Seibert, K. Evaluation of cyclooxygenase-2 inhibitor for potential chemopreventive properties in colon carcinogenesis. Cancer Res., 56: 4566-4569, 1996．
39． Takahashi, M., Fukutake, M., Yokota, S., Ishida, K., Wakabayashi, K., and Sugimura, T. Suppression of azoxymethane-induced aberrant crypt foci in rat colon by nimesulide, a selective inhibitor of cyclooxygenase 2． J. Cancer Res.Clin.Oncol.,122: 219-222, 1996．
40． DuBois, R. N., Shao, J., Tsujii, M., Sheng, H., and Beauchamp, R. D. G1 delay in cells overexpressing prostaglandin endoperoxide synthase-2． Cancer Res., 56: 733-737, 1996．
41． Marnett, L. J. Generation of mutagens during arachidonic acid metabolism. Cancer Metastasis Rev., 73: 303-308, 1994．
42． Tortora, G., Caputo, R., Damiano, V., Melisi, D., Bianco, R., Fontanini, G, Veneziani, B. M., De Placido, S., Bianco, A. R., and Ciardiello, F. Combination of a Selective Cyclooxygenase-2 Inhibitor with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor ZD1839 and Protein Kinase A Antisense Causes Cooperative Antitumor and Antiangiogenic Effect. Clin.Cancer Res., 9: 1566-1572, 2003．
43． Kirkpatrick, K., Ogunkolade, W., Elkak, A., Bustin, S., Jenkins, P., Ghilchik, M., and Mokbel, K. The mRNA expression of cyclo-oxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in human breast cancer. Curr.Med.Res.Opin., 18: 237-241, 2002．
44． Yamauchi, T., Watanabe, M., Hasegawa, H., Nishibori, H., Ishii, Y., Tatematsu, H., Yamamoto, K., Kubota, T., and Kitajima, M. The potential for a selective cyclooxygenase-2 inhibitor in the prevention of liver metastasis in human colorectal cancer. Anticancer Res., 23: 245-249, 2003．
45． Heslin, M. J., Yan, I, Johnson, M. R., Weiss, H., Diasio, R. B., and Urist, M. M. Role of matrix metalloproteinases in colorectal carcinogenesis. Ann.Surg., 233: 786-792,2001．
46． Nagatsuka, I., Yamada, N., Shimizu, S., Ohira, M., Nishino, H., Seki, S., and Hirakawa, K. Inhibitory effect of a selective cyclooxygenase-2 inhibitor on liver metastasis of colon cancer. Int. J.Cancer, 100: 515-519, 2002．
47． Vadlamudi, R., Mandal, M., Adam, L., Steinbach, G., Mendelsohn, J., and Kumar, R. Regulation of cyclooxygenase-2 pathway by HER2 receptor. Oncogene, 18: 305-314, 1999．
48． Hong, S. H., Avis, I., Vos, M. D., Martinez, A., Treston, A. M., and Mulshine, J. L. Relationship of arachidonic acid metabolizing enzyme expression in epithelial cancer cell lines to the growth effect of selective biochemical inhibitors. Cancer Res., 59: 2223-2228, 1999．
49． Lipsky, P. E. The clinical potential of cyclooxygenase-2-specific inhibitors. Am.J.Med., 106: 51S-57S, 1999．
50． Ryan, A. R., Rosita, A. R., Kamarul, A. K., and Qureshi, A. COX-2 inhibitors: a potential target for drug therapy in the management of colorectal cancer. Med.J.Malaysia, 54: 293-295, 1999．
51． Boudreau, M. D., Sohn, K. H., Rhee, S. H., Lee, S. W., Hunt, J. D., and Hwang, D. H. Suppression of tumor cell growth both in nude mice and in culture by n-3 polyunsaturated fatty acids, mediation through cyclooxygenase-independent pathways. Cancer Res., 61: 1386-1391, 2001．
52． Taylor, M. T., Lawson, K. R, Ignatenko, N. A., Marek, S. E., Stringer, D. E., Skovan, B. A., and Gerner, E. W. Sulindac sulfone inhibits K-ras-dependent cyclooxygenase-2 expression in human colon cancer cells. Cancer Res., 60: 6607-6610, 2000．
53． Kojima, M., Morisaki, T., Izuhara, K., Uchiyama, A., Matsunari, Y., Katano, M., and Tanaka, M. Lipopolysaccharide increases cyclo-oxygenase-2 expression in a colon carcinoma cell line through nuclear factor-kappa B activation. Oncogene, 19． 1225-1231,2000．
54． Fosslien, E. Molecular pathology of cyclooxygenase-2 in neoplasia. Ann.Clin.Lab Sci., 30: 3-21, 2000．
55． Stark L.A., Loveridge C.J., and Dunlop M.G. Interaction between beta-catenin and NF-kappa B-a possible mechanism for aspirin-induced repression of NF-kappa B activity and apoptosis in colorectal cancer cells. Proceedings of the American Association for Cancer Research 94th annual Meeting, 44: 4249, 2003
56． Ding H., Gibson-D'Ambrosio R. E., Han C., and D'Ambrosio S. M. Piroxicam selectively targets human premalignant and malignant oral cells via COX dependent and independent pathways. Proceedings of the American Association for Cancer Research 94th annual Meeting, 44: 4915, 2003
57． Yip-Schneider M. T., Sweeney C. J., Nakshatri H., Marshall M. S., and Schmidt C. M. Nuclear factor-kappa B inhibition augments growth suppression by sulindac in pancreatic cancer cells. Proceedings of the American Association for Cancer Research 94th annual Meeting, 44: 6365, 2003
58． Sinicrope, F. A, Lemoine, M., Xi, L., Lynch, P. M., Cleary, K. R., Shen, Y., and Frazier, M. L. Reduced expression of cyclooxygenase 2 proteins in hereditary nonpolyposis colorectal cancers relative to sporadic cancers. Gastroenterology, 117: 350-358, 1999．
59． Toyota, M., Shen, L., Ohe-Toyota, M., Hamilton, S. R., Sinicrope, F. A., and Issa, J. P. Aberrant methylation of the Cyclooxygenase 2 CpG island in colorectal tumors. Cancer Res., 60: 4044-4048, 2000．