ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular ...ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular carcinoma (HCC), the significance of COX-2 in progression of HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationship with VEGF level in HCC. METHODS: Fresh tumor tissues were obtained from 100 patients who underwent resection of HCC. COX-2 protein expression was examined by immunohistochemistry, and quantitatively by an enzyme immunometric assay (EIA) of tumor cytosolic COX-2 levels. Tumor cytosolic VEGF levels were measured by an ELISA. RESULTS: Immunostaining showed expression of COX-2 in tumor cells. Tumor cytosolic COX-2 levels correlated with VEGF levels (r = 0.469,P<0.001). Correlation with clinicopathological features showed significantly higher tumor cytosolic COX-2 levels in the presence of multiple tumors (P = 0.027), venous invasion (P = 0.030), microsatellite lesions (P=0.037) and advanced tumor stage (P = 0.008). Higher tumor cytosolic COX-2 levels were associated with worse patient survival. CONCLUSION: This study shows that elevated tumor COX-2 levels correlate with elevated VEGF levels and invasiveness in HCC, suggesting that COX-2 plays a significant role in the progression of HCC.展开更多
Selective cyclooxygenase （COX）-2 inhibitors （coxibs） were developed as one of the anti-inflammatory drugs to avoid the various side effects of non-steroidal anti-inflammatory drugs （NSAIDs）. However, coxibs also...Selective cyclooxygenase （COX）-2 inhibitors （coxibs） were developed as one of the anti-inflammatory drugs to avoid the various side effects of non-steroidal anti-inflammatory drugs （NSAIDs）. However, coxibs also have an ability to inhibit tumor development of various kinds the same way that NSAIDs do. Many experimental studies using cell lines and animal models demonstrated an ability to prevent tumor proliferation of COX-2 inhibitors. After performing a randomized study for polyp chemoprevention study in patients with familial adenomatous polyposis （FAP）, which showed that the treatment with celecoxib, one of the coxibs, significantly reduced the number of colorectal polyps in 2000, the U.S. Food and Drug Administration （FDA） immediately approved the clinical use of celecoxib for FAP patients. However, some coxibs were recently reported to increase the risk of serious cardiovascular events including heart attack and stroke. In this article we review a role of COX-2 in carcinogenesis of gastrointestinal tract, such as the esophagus, stomach and colorectum, and also analyze the prospect of coxibs for chemoprevention of gastrointestinal tract tumors.展开更多
Aberrant expression and signaling of epidermal growth factor receptor (ErbB) family receptor tyrosine kinases, most notably that of ErbB2 and ErbB1, have been implicated in the molecular pathogenesis of intrahepatic c...Aberrant expression and signaling of epidermal growth factor receptor (ErbB) family receptor tyrosine kinases, most notably that of ErbB2 and ErbB1, have been implicated in the molecular pathogenesis of intrahepatic cholangiocarcinoma. Constitutive overexpression of ErbB2 and/or ErbB1 in malignant cholangiocytes has raised interest in the possibility that agents which selectively target these receptors could potentially be effective in cholangiocarcinoma therapy. However, current experience with such ErbB-directed therapies have at best produced only modest responses in patients with biliary tract cancers. This review provides a comprehensive and critical analysis of both preclinical and clinical studies aimed at assessing the role of altered ErbB2 and/or ErbB1 expression, genetic modifications, and dysregulated signaling on cholangiocarcinoma development and progression. Specific limitations in experimental approaches that have been used to assess human cholangiocarcinoma specimens for ErbB2 and/or ErbB1 overexpression and gene amplification are discussed. In addition, current rodent models of intrahepatic cholangiocarcinogenesis associated with constitutive ErbB2 overexpression are reviewed. Select interactive relationships between ErbB2 or ErbB1 with other relevant molecular signaling pathways associated with intrahepatic cholangiocarcinoma development and progression are also detailed, including those linking ErbB receptors to bile acid, cyclooxygenase-2,interleukin-6/gp130, transmembrane mucins, hepatocyte growth factor/Met, and vascular endothelial growth factor signaling. Lastly, various factors that can limit therapeutic efficacy of ErbB-targeted agents against cholangiocarcinoma are considered.展开更多
Although the incidence of gastric cancer has been declining in recent decades,it remains a major public health issue as the second leading cause of cancer death worldwide.In China,gastric cancer is still the main caus...Although the incidence of gastric cancer has been declining in recent decades,it remains a major public health issue as the second leading cause of cancer death worldwide.In China,gastric cancer is still the main cause of death in patients with malignant tumors.Most patients are diagnosed at an advanced stage and mortality is high.Cyclooxygenase-2(COX-2)is a ratelimiting enzyme in prostanoid synthesis and plays an important role in the development and progression of gastric cancer.The expression of COX-2 in gastric cancer is upregulated and its molecular mechanisms have been investigated.Helicobacter pylori infection,tumor suppressor gene mutation and the activation of nuclear factor-kappa B may be responsible for the elevated expression of COX-2 in gastric cancer.The mechanisms of COX-2 in the development and progression of gastric cancer are probably through promoting the proliferation of gastric cancer cells,while inhibiting apoptosis,assisting angiogenesis and lymphatic metastasis,and participating in cancer invasion and immunosuppression.This review is intended to discuss,comment and summarize recent research progress on the role of COX-2 in gastric cancer development and progression,and elucidate the molecular mechanisms which might be involved in the carcinogenesis.展开更多
Many epidemiological studies demonstrate that treatment with non-steroidal anti-inflammatory drugs （NSAIDs） reduce the incidence and mortality of certain malignancies, especially gastrointestinal cancer. The cycloox...Many epidemiological studies demonstrate that treatment with non-steroidal anti-inflammatory drugs （NSAIDs） reduce the incidence and mortality of certain malignancies, especially gastrointestinal cancer. The cyclooxygenase （COX） enzymes are well-known targets of NSAIDs. However, conventional NSAIDs nonselectively inhibit both the constitutive form COX-1, and the inducible form COX-2. Recent evidence indicates that COX-2 is an important molecular target for anticancer therapies. Its expression is undetectable in most normal tissues, and is highly induced by proinflammatory cytokines, mitogens, tumor promoters and growth factors. It is now well-established that COX-2 is chronically overexpressed in many premalignant, malignant, and metastastic cancers, including hepatocellular carcinoma （HCC）. Overexpression of COX-2 in patients with HCC is generally higher in welldifferentiated HCCs compared with less-differentiated HCCs or histologically normal liver, suggesting that COX-2 may be involved in the early stages of hepatocarcinogenesis, and increased expression of COX-2 in noncancerous liver tissue has been significantly associated with shorter disease-free survival in patients with HCC. In tumors, overexpression of COX-2 leads to an increase in prostaglandin （PG） levels, which affect many mechanisms involved in carcinogenesis, such as angiogenesis, inhibition of apoptosis, stimulation of cell growth as well as the invasiveness and metastatic potential of tumor cells. The availability of novel agents that selectively inhibit COX-2 （COXIB）, has contributed to shedding light on the role of this molecule. Experimental studies on animal models of liver cancer have shown that NSAIDs, including both selective and non-selective COX-2 inhibitors, exert chemopreventive as well as therapeutic effects. However, the key mechanism by which COX-2 inhibitors affect HCC cell growth is as yet not fully understood. Increasing evidence suggests the involvement of molecular targets other than COX-2 in the antiprol展开更多
背景与目的:研究表明,环氧化酶-2(cyclooxygenase-2,COX-2)及信号转导和转录活化因子(signal transducers and activators of transcription,STAT)的活化均与肿瘤的发生、发展密切相关。本研究旨在检测COX-2、p-Stat3及p-Stat5在不同食...背景与目的:研究表明,环氧化酶-2(cyclooxygenase-2,COX-2)及信号转导和转录活化因子(signal transducers and activators of transcription,STAT)的活化均与肿瘤的发生、发展密切相关。本研究旨在检测COX-2、p-Stat3及p-Stat5在不同食管病变组织中的表达,并探讨三者在食管癌组织中表达的意义。方法:采用免疫组织化学SP法检测59例食管鳞状细胞癌、24例鳞状上皮非典型增生及18例正常鳞状上皮中COX-2、p-Stat3及p-Stat5的表达,并分析其与临床病理特征的关系。结果:COX-2在食管正常鳞状上皮、非典型增生和鳞状细胞癌的免疫组化染色平均积分分别为0.83±0.46、1.85±1.24和2.10±1.77,鳞状细胞癌与非典型增生组织的COX-2表达高于正常鳞状上皮,差异有统计学意义(P<0.05);在正常鳞状上皮、非典型增生及鳞状细胞癌中,p-Stat3的平均积分分别为0、0.76±0.59、2.83±1.27,p-Stat5分别为1.98±0.78、3.92±0.41、5.02±0.34,三种组织间两两比较,p-Stat3和p-Stat5表达的差异均有统计学意义(P<0.05)。食管鳞癌中淋巴结转移者及分化较低者COX-2表达低(P<0.05),且不同浸润深度的组织中p-Stat3表达的差异有统计学意义(P<0.05)。不同临床病理特征的组织中p-Stat5表达的差异无统计学意义(P>0.05)。COX-2、p-Stat3及p-Stat5三者的表达之间呈正相关。结论:COX-2可能在食管癌变早期具有重要作用,COX-2高表达可能是食管癌变过程中的早期事件。Stat3的磷酸化与食管癌的进展相关。展开更多
基金Supported by the Sun C.Y. Research Foundation for Hepatobiliary and Pancreatic Surgery of the University of Hong Kong
文摘ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular carcinoma (HCC), the significance of COX-2 in progression of HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationship with VEGF level in HCC. METHODS: Fresh tumor tissues were obtained from 100 patients who underwent resection of HCC. COX-2 protein expression was examined by immunohistochemistry, and quantitatively by an enzyme immunometric assay (EIA) of tumor cytosolic COX-2 levels. Tumor cytosolic VEGF levels were measured by an ELISA. RESULTS: Immunostaining showed expression of COX-2 in tumor cells. Tumor cytosolic COX-2 levels correlated with VEGF levels (r = 0.469,P<0.001). Correlation with clinicopathological features showed significantly higher tumor cytosolic COX-2 levels in the presence of multiple tumors (P = 0.027), venous invasion (P = 0.030), microsatellite lesions (P=0.037) and advanced tumor stage (P = 0.008). Higher tumor cytosolic COX-2 levels were associated with worse patient survival. CONCLUSION: This study shows that elevated tumor COX-2 levels correlate with elevated VEGF levels and invasiveness in HCC, suggesting that COX-2 plays a significant role in the progression of HCC.
文摘Selective cyclooxygenase （COX）-2 inhibitors （coxibs） were developed as one of the anti-inflammatory drugs to avoid the various side effects of non-steroidal anti-inflammatory drugs （NSAIDs）. However, coxibs also have an ability to inhibit tumor development of various kinds the same way that NSAIDs do. Many experimental studies using cell lines and animal models demonstrated an ability to prevent tumor proliferation of COX-2 inhibitors. After performing a randomized study for polyp chemoprevention study in patients with familial adenomatous polyposis （FAP）, which showed that the treatment with celecoxib, one of the coxibs, significantly reduced the number of colorectal polyps in 2000, the U.S. Food and Drug Administration （FDA） immediately approved the clinical use of celecoxib for FAP patients. However, some coxibs were recently reported to increase the risk of serious cardiovascular events including heart attack and stroke. In this article we review a role of COX-2 in carcinogenesis of gastrointestinal tract, such as the esophagus, stomach and colorectum, and also analyze the prospect of coxibs for chemoprevention of gastrointestinal tract tumors.
基金National Institutes of Health Grants,R01 CA 83650 and R01 CA 39225 to A.E.S.
文摘Aberrant expression and signaling of epidermal growth factor receptor (ErbB) family receptor tyrosine kinases, most notably that of ErbB2 and ErbB1, have been implicated in the molecular pathogenesis of intrahepatic cholangiocarcinoma. Constitutive overexpression of ErbB2 and/or ErbB1 in malignant cholangiocytes has raised interest in the possibility that agents which selectively target these receptors could potentially be effective in cholangiocarcinoma therapy. However, current experience with such ErbB-directed therapies have at best produced only modest responses in patients with biliary tract cancers. This review provides a comprehensive and critical analysis of both preclinical and clinical studies aimed at assessing the role of altered ErbB2 and/or ErbB1 expression, genetic modifications, and dysregulated signaling on cholangiocarcinoma development and progression. Specific limitations in experimental approaches that have been used to assess human cholangiocarcinoma specimens for ErbB2 and/or ErbB1 overexpression and gene amplification are discussed. In addition, current rodent models of intrahepatic cholangiocarcinogenesis associated with constitutive ErbB2 overexpression are reviewed. Select interactive relationships between ErbB2 or ErbB1 with other relevant molecular signaling pathways associated with intrahepatic cholangiocarcinoma development and progression are also detailed, including those linking ErbB receptors to bile acid, cyclooxygenase-2,interleukin-6/gp130, transmembrane mucins, hepatocyte growth factor/Met, and vascular endothelial growth factor signaling. Lastly, various factors that can limit therapeutic efficacy of ErbB-targeted agents against cholangiocarcinoma are considered.
基金Supported by Research Grant for Key Clinical Discipline Construction of Shanghai Municipality,China,No.ZK2012B20
文摘Although the incidence of gastric cancer has been declining in recent decades,it remains a major public health issue as the second leading cause of cancer death worldwide.In China,gastric cancer is still the main cause of death in patients with malignant tumors.Most patients are diagnosed at an advanced stage and mortality is high.Cyclooxygenase-2(COX-2)is a ratelimiting enzyme in prostanoid synthesis and plays an important role in the development and progression of gastric cancer.The expression of COX-2 in gastric cancer is upregulated and its molecular mechanisms have been investigated.Helicobacter pylori infection,tumor suppressor gene mutation and the activation of nuclear factor-kappa B may be responsible for the elevated expression of COX-2 in gastric cancer.The mechanisms of COX-2 in the development and progression of gastric cancer are probably through promoting the proliferation of gastric cancer cells,while inhibiting apoptosis,assisting angiogenesis and lymphatic metastasis,and participating in cancer invasion and immunosuppression.This review is intended to discuss,comment and summarize recent research progress on the role of COX-2 in gastric cancer development and progression,and elucidate the molecular mechanisms which might be involved in the carcinogenesis.
基金Supported by a grant from the Associazione Italiana per la Ricerca sul Cancro and from the Italian Ministero dell'Universitàedella Ricerca Scientifica (ex 60%, year 2003)
文摘Many epidemiological studies demonstrate that treatment with non-steroidal anti-inflammatory drugs （NSAIDs） reduce the incidence and mortality of certain malignancies, especially gastrointestinal cancer. The cyclooxygenase （COX） enzymes are well-known targets of NSAIDs. However, conventional NSAIDs nonselectively inhibit both the constitutive form COX-1, and the inducible form COX-2. Recent evidence indicates that COX-2 is an important molecular target for anticancer therapies. Its expression is undetectable in most normal tissues, and is highly induced by proinflammatory cytokines, mitogens, tumor promoters and growth factors. It is now well-established that COX-2 is chronically overexpressed in many premalignant, malignant, and metastastic cancers, including hepatocellular carcinoma （HCC）. Overexpression of COX-2 in patients with HCC is generally higher in welldifferentiated HCCs compared with less-differentiated HCCs or histologically normal liver, suggesting that COX-2 may be involved in the early stages of hepatocarcinogenesis, and increased expression of COX-2 in noncancerous liver tissue has been significantly associated with shorter disease-free survival in patients with HCC. In tumors, overexpression of COX-2 leads to an increase in prostaglandin （PG） levels, which affect many mechanisms involved in carcinogenesis, such as angiogenesis, inhibition of apoptosis, stimulation of cell growth as well as the invasiveness and metastatic potential of tumor cells. The availability of novel agents that selectively inhibit COX-2 （COXIB）, has contributed to shedding light on the role of this molecule. Experimental studies on animal models of liver cancer have shown that NSAIDs, including both selective and non-selective COX-2 inhibitors, exert chemopreventive as well as therapeutic effects. However, the key mechanism by which COX-2 inhibitors affect HCC cell growth is as yet not fully understood. Increasing evidence suggests the involvement of molecular targets other than COX-2 in the antiprol
文摘背景与目的:研究表明,环氧化酶-2(cyclooxygenase-2,COX-2)及信号转导和转录活化因子(signal transducers and activators of transcription,STAT)的活化均与肿瘤的发生、发展密切相关。本研究旨在检测COX-2、p-Stat3及p-Stat5在不同食管病变组织中的表达,并探讨三者在食管癌组织中表达的意义。方法:采用免疫组织化学SP法检测59例食管鳞状细胞癌、24例鳞状上皮非典型增生及18例正常鳞状上皮中COX-2、p-Stat3及p-Stat5的表达,并分析其与临床病理特征的关系。结果:COX-2在食管正常鳞状上皮、非典型增生和鳞状细胞癌的免疫组化染色平均积分分别为0.83±0.46、1.85±1.24和2.10±1.77,鳞状细胞癌与非典型增生组织的COX-2表达高于正常鳞状上皮,差异有统计学意义(P<0.05);在正常鳞状上皮、非典型增生及鳞状细胞癌中,p-Stat3的平均积分分别为0、0.76±0.59、2.83±1.27,p-Stat5分别为1.98±0.78、3.92±0.41、5.02±0.34,三种组织间两两比较,p-Stat3和p-Stat5表达的差异均有统计学意义(P<0.05)。食管鳞癌中淋巴结转移者及分化较低者COX-2表达低(P<0.05),且不同浸润深度的组织中p-Stat3表达的差异有统计学意义(P<0.05)。不同临床病理特征的组织中p-Stat5表达的差异无统计学意义(P>0.05)。COX-2、p-Stat3及p-Stat5三者的表达之间呈正相关。结论:COX-2可能在食管癌变早期具有重要作用,COX-2高表达可能是食管癌变过程中的早期事件。Stat3的磷酸化与食管癌的进展相关。
