Cyclooxygenase-2 pathway correlates with VEGF expression in head and neck cancer. Implications for tumor angiogenesis and metastasis

[Primary and secondary prevention of skin cancer in organ transplant recipients]

Skin cancer constitutes the most frequently reported post-transplant malignancy in solid organ transplant recipients (OTR) worldwide. Whereas the risk for malignant melanoma is only moderately increased, non-melanoma skin cancers (NMSC) seem to thrive on chronic immunosuppression and account for up to 95% of post-transplant cutaneous malignancies. Compared to the general population cutaneous squamous cell carcinoma (SCC) and actinic keratoses (AK) characteristically show even higher incidences than basal cell carcinoma (BCC) and act as an indicator for the development of multiple primary cutaneous neoplasias and locally recurrent cancers (field cancerization). Early diagnosis and therapy of pre-malignant cutaneous lesions is crucial for the secondary prophylaxis of further invasive and highly aggressive skin cancers. High quality interdisciplinary care and prophylactic modalities, including consistent and sufficient UV protection, topical immunmodulatory therapies of UV-damaged skin areas, retinoid chemoprevention as well as tapering immunosuppressive treatment or the selection of immunosuppressants with proposed antiangiogenic properties like mTor-inhibitors may help to reduce the multiplicity of subsequent primary skin cancers in high-risk patients. Apart from the continuous need for educational intervention of OTR in the primary prophylaxis of post-transplant skin cancers, dermatologic care occupies a central position within the field of transplantation medicine in terms of pre- and post-transplantation dermatologic evaluation and therapy as well as the implication of timely and effective secondary preventive approaches in the management of this high-risk patient population.

Decreased risk of squamous cell carcinoma of the head and neck in users of nonsteroidal anti-inflammatory drugs

We evaluated the chemopreventive effect of nonsteroidal anti-inflammatory drug (NSAID) use in head and neck squamous cell carcinomas (HNSCC) by conducting a case-control study based on the administration of a standardized questionnaire to 71 incident HNSCC cases and same number of healthy controls. NSAID use was associated with a 75% reduction in risk of developing HNSCC. A significant risk reduction was noted in association with frequency of NSAID use. Restricting the analysis to aspirin users revealed a significant 90% reduction in risk of developing HNSCC. This study provides evidence for a significant reduction in the risk of developing HNSCC in users of NSAIDs, and specifically aspirin users.

Effects of Helicobacter pylori infection and hypergastrinemia on the growth of colonic adenoma

AIM: To investigate the association among gastrin level, Helicobacter pylori (H. pylori) infection and the development of colonic adenoma.

METHODS: Fasting serum samples from 48 patients with colonic adenomas and 43 demographically matched colonoscopy-negative controls were assayed for anti-H. pylori IgG and serum gastrin levels. Colonic adenoma patients received oral celecoxib for 6 months. At the end of the second, fourth and sixth months, serum gastrin levels were measured by radioimmunoassay (RIA) and H. pylori IgG antibody was analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS: The prevalence of H. pylori seropositivity was significantly higher in patients with colonic adenomas than in controls (68.8% vs 9.30%, P < 0.05). Similarly, median gastrin level was significantly higher in patients with colonic adenomas than in controls (72.7% vs 37.8%, P < 0.05). There was a positive correlation between H. pylori IgG antibody and serum gastrin level in colonic adenoma patients (r = 0.854, P < 0.001). Of note, hypergastrinemia was associated with distal colon distribution of adenomas, but not with adenoma number, size, grade or histological features. After celecoxib treatment, there were parallel falls in serum gastrin levels and H. pylori seropositivity in colonic adenoma patients.

CONCLUSION: Hypergastrinemia induced by H. pylori infection is associated with increased cyclooxygenase-2 (COX-2) expression in colonic adenoma, suggesting the possibility that gastrin up-regulates COX-2 expression in colonic adenoma. Celecoxib can obviously decrease H. pylori seropositivity and gastrin levels and inhibit the growth of colonic adenomas by down-regulating COX-2 expression.

Genetic deletion of COX-2 diminishes VEGF production in mouse retinal Müller cells

Non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit COX activity, reduce the production of retinal VEGF and neovascularization in relevant models of ocular disease. We hypothesized that COX-2 mediates VEGF production in retinal Müller cells, one of its primary sources in retinal neovascular disease. The purpose of this study was to determine the role of COX-2 and its products in VEGF expression and secretion. These studies have more clearly defined the role of COX-2 and COX-2-derived prostanoids in retinal angiogenesis. Müller cells derived from wild-type and COX-2 null mice were exposed to hypoxia for 0-24 h. COX-2 protein and activity were assessed by western blot analysis and GC-MS, respectively. VEGF production was assessed by ELISA. Wild-type mouse Müller cells were treated with vehicle (0.1% DMSO), 10 microM PGE(2), or PGE(2) + 5 microM H-89 (a PKA inhibitor), for 12 h. VEGF production was assessed by ELISA. Hypoxia significantly increased COX-2 protein (p < 0.05) and activity (p < 0.05), and VEGF production (p < 0.0003). COX-2 null Müller cells produced significantly less VEGF in response to hypoxia (p < 0.05). Of the prostanoids, PGE(2) was significantly increased by hypoxia (p < 0.02). Exogenous PGE(2) significantly increased VEGF production by Müller cells (p < 0.0039), and this effect was inhibited by H-89 (p < 0.055). These data demonstrate that hypoxia induces COX-2, prostanoid production, and VEGF synthesis in Müller cells, and that VEGF production is at least partially COX-2-dependent. Our study suggests that PGE(2), signaling through the EP(2) and/or EP(4) receptor and PKA, mediates the VEGF response of Müller cells.

Expression of cyclooxygenase-2, glucose transporter-1 and angiogenesis in gallbladder carcinomas and their impact on prognosis

OBJECTIVE

To investigate the angiogenic and prognostic role of cyclooxygenase-2 (COX-2) in gallbladder carcinomas. We assume COX-2 overexpression, neoangiogenesis and glucose transporter-1 (GLUT-1) to be involved in disease progression.

MATERIAL AND METHODS

The carcinoma tissues of 56 patients with gallbladder carcinomas were studied immunohistochemically for the expression of COX-2, GLUT-1 and micro-vessel density. The results were correlated with clinico-pathological features and survival/prognosis.

RESULTS

The overexpression of COX-2 in gallbladder carcinomas was significantly associated with increased angiogenesis and GLUT-1 expression. Neither angiogenesis nor the grade of the tumour correlate significantly with poor survival. Age, gender and a strong GLUT-1 expression were significant factors of adverse prognosis.

CONCLUSIONS

Next to age and gender of patients, hypoxia of gallbladder tumours is a factor influencing survival. Among hypoxic factors, GLUT-1 expression is an important (significant) denominator of poor prognosis in gallbladder carcinomas, but not COX-2 nor angiogenesis.

Kaposi's sarcoma associated herpes virus (KSHV) induced COX-2: a key factor in latency, inflammation, angiogenesis, cell survival and invasion

Kaposi's sarcoma (KS), an enigmatic endothelial cell vascular neoplasm, is characterized by the proliferation of spindle shaped endothelial cells, inflammatory cytokines (ICs), growth factors (GFs) and angiogenic factors. KSHV is etiologically linked to KS and expresses its latent genes in KS lesion endothelial cells. Primary infection of human micro vascular endothelial cells (HMVEC-d) results in the establishment of latent infection and reprogramming of host genes, and cyclooxygenase-2 (COX-2) is one of the highly up-regulated genes. Our previous study suggested a role for COX-2 in the establishment and maintenance of KSHV latency. Here, we examined the role of COX-2 in the induction of ICs, GFs, angiogenesis and invasive events occurring during KSHV de novo infection of endothelial cells. A significant amount of COX-2 was detected in KS tissue sections. Telomerase-immortalized human umbilical vein endothelial cells supporting KSHV stable latency (TIVE-LTC) expressed elevated levels of functional COX-2 and microsomal PGE2 synthase (m-PGES), and secreted the predominant eicosanoid inflammatory metabolite PGE2. Infected HMVEC-d and TIVE-LTC cells secreted a variety of ICs, GFs, angiogenic factors and matrix metalloproteinases (MMPs), which were significantly abrogated by COX-2 inhibition either by chemical inhibitors or by siRNA. The ability of these factors to induce tube formation of uninfected endothelial cells was also inhibited. PGE2, secreted early during KSHV infection, profoundly increased the adhesion of uninfected endothelial cells to fibronectin by activating the small G protein Rac1. COX-2 inhibition considerably reduced KSHV latent ORF73 gene expression and survival of TIVE-LTC cells. Collectively, these studies underscore the pivotal role of KSHV induced COX-2/PGE2 in creating KS lesion like microenvironment during de novo infection. Since COX-2 plays multiple roles in KSHV latent gene expression, which themselves are powerful mediators of cytokine induction, anti-apoptosis, cell survival and viral genome maintainence, effective inhibition of COX-2 via well-characterized clinically approved COX-2 inhibitors could potentially be used in treatment to control latent KSHV infection and ameliorate KS.

Kaposi's sarcoma associated herpes virus (KSHV), with a 160 kb DNA genome, has evolved with two distinct life cycle phases, namely latency and lytic replication. KS, a complex angioproliferative disease, is regulated by a balance between pro-angiogenic and anti-angiogenic factors. In our previous study, we showed that KSHV modulates host factors COX-2/PGE2 for its own advantage to promote its latent (persistent) infection. The premise that COX-2 is involved in growth and progression of several types of solid cancers and inflammation associated diseases has been well documented but has never been studied in KS. Here, utilizing COX-2 inhibition strategies, including chemical inhibition and a gene silencing approach, we systematically identified the potential role of KSHV induced COX-2/PGE2 in viral pathogenesis related events such as secretion of inflammatory and angiogenic cytokines, MMPs and cell adhesion in de novo infected or latently infected endothelial cells. We report that COX-2/PGE2 inhibition down-regulates viral latent gene expression and survival of latently infected endothelial cells. The data emanating from our in vitro studies is valuable, informative and requires further examination using an in vitro angiogenic model and in vivo nude mice model to further validate COX-2 as a novel therapeutic to target latent infection and the associated diseases like KS.

Elevated levels of urinary prostaglandin e metabolite indicate a poor prognosis in ever smoker head and neck squamous cell carcinoma patients

Cyclooxygenase (COX)-derived prostaglandin E(2) (PGE(2)) plays a role in the development and progression of several tumor types including head and neck squamous cell carcinoma (HNSCC). Measurements of urinary PGE metabolite (PGE-M) can be used as an index of systemic PGE(2) production. In ever smokers, increased levels of urinary PGE-M reflect increased COX-2 activity. In this study, we determined whether baseline levels of urinary PGE-M were prognostic for ever smoker HNSCC patients. A retrospective chart review of ever smoker HNSCC patients treated with curative intent was done. Fifteen of 31 evaluable patients developed progressive disease (recurrence or a second primary tumor) after a median follow-up of 38 months. There were no statistically significant differences between patients with (n = 15) or without disease progression (n = 16) with regard to stage, site, treatment received, smoking status, and aspirin use during follow-up. Median urinary PGE-M levels were significantly higher in HNSCC patients with disease progression (21.7 ng/mg creatinine) compared with patients without (13.35 ng/mg creatinine; P = 0.03). Importantly, patients with high baseline levels of urinary PGE-M had a significantly greater risk of disease progression (hazard ratio, 4.76, 95% CI, 1.31-17.30; P < 0.01) and death (hazard ratio, 9.54; 95% CI, 1.17-77.7; P = 0.01) than patients with low baseline levels of urinary PGE-M. These differences were most evident among patients with early-stage disease. Taken together, our findings suggest that high baseline levels of urinary PGE-M indicate a poor prognosis in HNSCC patients. Possibly, HNSCC patients with high COX-2 activity manifested by elevated urinary PGE-M will benefit from treatment with a COX-2 inhibitor.

Role of cytosolic phospholipase A(2) in retinal neovascularization

PURPOSE

To identify and characterize the role of cytosolic phospholipase A(2) (cPLA(2)) in retinal angiogenesis using relevant cell-based assays and a rodent model of retinopathy of prematurity.

METHODS

The phosphorylation states of cPLA(2) and p38 MAP kinase and the expression of COX-2 were assessed by Western blot analysis in rat Müller cells. The activities of PLA(2) enzymes in rat retinal lysates were assessed using a commercially available assay. Prostaglandin E(2) (PGE(2)) and VEGF levels in Müller cell-conditioned medium and in retinal tissue samples were measured by ELISA. Rat retinal microvascular endothelial cell proliferation was measured using a BrdU assay. Efficacy of the cPLA(2) inhibitor CAY10502 was tested using the rat model of oxygen-induced retinopathy (OIR) in which neovascularization (NV) was assessed by computer-assisted image analysis.

RESULTS

In Müller cells, hypoxia increased the phosphorylation of cPLA(2) and p38 MAP kinase by 4-fold and 3-fold respectively. The cPLA(2) inhibitor CAY10502 decreased hypoxia-induced PGE(2) and VEGF levels in Müller cell-conditioned medium by 68.6% (P < 0.001) and 46.6% (P < 0.001), respectively. Retinal cPLA(2) activity peaked 1 day after oxygen exposure in OIR rats. CAY10502 (250 nM) decreased OIR-induced retinal PGE(2) and VEGF levels by 69% (P < 0.001) and 40.2% (P < 0.01), respectively. Intravitreal injection of 100 nM CAY10502 decreased retinal NV by 53.1% (P < 0.0001).

CONCLUSIONS

cPLA(2) liberates arachidonic acid, the substrate for prostaglandin (PG) production by the cyclooxygenase enzymes. PGs can exert a proangiogenic influence by inducing VEGF production and by stimulating angiogenic behaviors in vascular endothelial cells. Inhibition of cPLA(2) inhibits the production of proangiogenic PGs. Thus, cPLA(2) inhibition has a significant influence on pathologic retinal angiogenesis.

Phosphorylated epidermal growth factor receptor and cyclooxygenase-2 expression in localized non-small cell lung cancer

PURPOSE

The prognostic significance of epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) expression remains unestablished, although EGFR and COX-2 are frequently overexpressed in non-small cell lung cancer (NSCLC). Considering the importance of EGFR activation after ligand binding, however, the expression of phosphorylated EGFR (p-EGFR) may have more significance in predicting tumor aggressiveness in NSCLC than either EGFR or COX-2 expression.

PATIENTS AND METHODS

We studied the relationships between p-EGFR, EGFR, and COX-2 overexpression and examined their association with prognosis in localized NSCLC. The expression of p-EGFR, EGFR, and COX-2 was studied by immunohistochemistry in 77 surgically-resected stage I/II NSCLC cases. EGFR mutational status was determined by sequencing exons 18-21. Correlation of expression with clinical outcome and other biomarkers, including Ki-67 and microvessel density (MVD), was also examined.

RESULTS

Out of the 77 patients, EGFR overexpression was observed in 37 (48.1%), p-EGFR expression was found in 22 (28.6%), and COX-2 overexpression was seen in 45 (58.4%). Expression of p-EGFR was associated with COX-2 overexpression (P = 0.047), but not EGFR overexpression or high Ki-67 (P = 0.087 and P = 0.092, respectively). COX-2 overexpression was significantly associated with high Ki-67 (P = 0.011). Expression of p-EGFR correlated with lower disease-free survival (P = 0.045), but not overall survival. Neither EGFR nor COX-2 overexpression was associated with prognosis.

CONCLUSION

p-EGFR appears to be a better indicator for lower disease-free survival than EGFR overexpression itself in localized NSCLC. Pathways other than EGFR activation may influence COX-2 overexpression.

Inhibition of arachidonic acid metabolism and its implication on cell proliferation and tumour-angiogenesis

Arachidonic acid (AA) and its metabolites have recently generated a heightened interest due to growing evidence of their significant role in cancer biology. Thus, inhibitors of the AA cascade, first and foremost COX inhibitors, which have originally been of interest in the treatment of inflammatory conditions and certain types of cardiovascular disease, are now attracting attention as an arsenal against cancer. An increasing number of investigations support their role in cancer chemoprevention, although the precise molecular mechanisms that link levels of AA, and its metabolites, with cancer progression have still to be elucidated. This article provides an overview of the AA cascade and focuses on the roles of its inhibitors and their implication in cancer treatment. In particular, emphasis is placed on the inhibition of cell proliferation and neo-angiogenesis through inhibition of the enzymes COX-2, 5-LOX and CYP450. Downstream effects of inhibition of AA metabolites are analysed and the molecular mechanisms of action of a selected number of inhibitors of catalytic pathways reviewed. Lastly, the benefits of dietary omega-3 fatty acids and their mechanisms of action leading to reduced cancer risk and impeded cancer cell growth are mentioned. Finally, a proposal is put forward, suggesting a novel and integrated approach in viewing the molecular mechanisms and complex interactions responsible for the involvement of AA metabolites in carcinogenesis and the protective effects of omega-3 fatty acids in inflammation and tumour prevention.

Insulin-like growth factor binding protein-7 (IGFBP7) blocks vascular endothelial cell growth factor (VEGF)-induced angiogenesis in human vascular endothelial cells

Insulin-like growth factor binding protein-7 (IGFBP7) and vascular endothelial growth factor (VEGF) are expressed in vascular endothelial cells in several tumor types. In this study, we examined the effect of IGFBP7 on VEGF-induced tube formation in cultured human umbilical vein endothelial cells (HUVECs) and its potential action in the modulation of VEGF signaling in vascular cells. IGFBP7 treatment suppressed VEGF-induced tube formation, proliferation, and the phosphorylation of mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinase (ERK) 1/2 in HUVECs. IGFBP7 attenuated VEGF-enhanced cyclooxygenase (COX)-2 and VEGF mRNA expression, and prostaglandin E(2) secretion. Knocking down endogenous IGFBP7 enhanced COX-2 and VEGF mRNA expression. A significant increase in IGFBP7-induced caspases was not observed in the presence of VEGF. These findings indicate that IGFBP7 can modulate the stimulatory effect of VEGF on angiogenesis by interfering with VEGF expression as well as VEGF signaling and not by inducing apoptosis.

Molecular target approaches in head and neck cancer: epidermal growth factor receptor and beyond

Approximately 50,000 new cases of head and neck squamous cell carcinoma (HNSCC) will be diagnosed in the United States in 2009. Although the gradual decline in smoking rates in the United States is a highly favorable trend, the future global HNSCC incidence will likely reflect the increased marketing and penetration of tobacco products across several of our most populous countries. Although modern surgery, radiation, and conventional chemotherapy strategies for HNSCC continue to provide gradual improvement in outcome, the first molecular targeting approach to show a survival advantage for HNSCC patients has recently emerged in the context of epidermal growth factor receptor biology. The scientific background and current challenges accompanying this recent advance are described in this article as are several additional promising molecular targets for HNSCC. There is cautious anticipation that the logical advancement of molecular targeting agents in conjunction with radiation may afford increased cure rates and diminished normal tissue toxicity profiles for HNSCC patients over the years to come.

[Down-regulation of survivin in growth inhibition of hepatoma cells induced by a selective cyclooxygenase-2 inhibitor]

BACKGROUND/AIMS

Cyclooxygenase-2 (COX-2) inhibitors reportedly inhibit the growth of hepatocellular carcinoma (HCC) via caspase-dependent or caspase-independent apoptosis, which is due to COX-2 being associated with hepatocarcinogenesis. Survivin is highly expressed in most human cancers, but the mechanism regulating survivin expression remains unclear. We investigated the regulatory expression of survivin in selective-COX-2-inhibitor-induced growth inhibition of hepatoma cells.

METHODS

After treatment with NS-398 (a selective COX-2 inhibitor) at various concentrations (10, 50, 100, 150, and 200 micrometer), the growth inhibition of Hep3B hepatoma cells was assessed by an MTT cell-viability assay, DNA fragmentation gel analysis, and flow cytometry. The expression of survivin transcript was analyzed by reverse-transcription polymerase chain reactions.

RESULTS

NS-398 inhibited the growth of hepatoma cells by an amount dependent on the concentration and the time since treatment. Apoptotic DNA ladder and flow-cytometry shifting to the sub-G1 phase were revealed in NS-398-induced growth inhibition of hepatoma cells. NS-398 suppressed the expression of the survivin gene in a concentration- and time-dependent manner.

CONCLUSIONS

Survivin was down-regulated in the growth inhibition of hepatoma cells induced by a selective COX-2 inhibitor, NS-398, in a concentration- and time-dependent manner. These results suggest the therapeutic inhibition of COX-2 via suppression of survivin in HCC.

Microcirculatory alteration in low-grade gastric mucosa-associated lymphoma by Helicobacter heilmannii infection: its relation to vascular endothelial growth factor and cyclooxygenase-2

BACKGROUND

There are clinical reports that Helicobacter heilmannii, as well as Helicobacter pylori, has been clinically reported to cause gastric low-grade mucosa-associated lymphoid tissue-type (MALT) lymphoma, although its precise mechanism remains to be clarified. Thus, the present study was undertaken to elucidate the alteration of the microcirculatory structure and the relation to angiogenetic factors in mice infected with H. heilmannii for 3 and 6 months.

METHODS

Immunohistochemical studies have been performed by FITC-dextran intra-aortic infusion or CD31, vascular endothelial growth factor-A, cyclooxygenase 2 antibodies using our recently established model of gastric mucosa-associated lymphoid tissue-type gastric B-cell lymphoma in C57BL/6 mice.

RESULTS

Increased microcirculatory network was recognized surrounding the MALT lymphoma tissues by both the FITC-dextran infusion method and CD31 immunoreactivity. Vascular endothelial growth factor-A immunoreactivity was recognized within the lymphoma tissues as well as in the marginal area, while cyclooxygenase-2 immunoreactivity was localized in the area surrounding the MALT lymphoma tissues.

CONCLUSION

Increased microvascular network as well as enhanced VEGF-A immunoreactivity was shown to be related to expansion of the MALT lymphoma formed by Helicobacter heilmannii infection.

Modulation of cyclooxygenase in endothelial cells by fibronectin: relevance to angiogenesis

Cyclooxygenases (COX), which catalyze the formation of prostaglandins (PGs), have been implicated in angiogenesis. Adhesion of endothelial cells (ECs) to extracellular matrix (ECM) induces the expression of COX-2 and PG production. The present study was carried out to analyze the influence of the adhesive ECM protein, fibronectin (FN), in modulating COX expression and its implications to angiogenesis using in vitro cultures of human umbilical vein ECs. RT-PCR analysis showed that the level of COX-2 mRNA was significantly high while that of COX-1 decreased in ECs maintained on FN. On treatment with p38 MAPK inhibitor and anti-alpha(5)beta(1) integrin antibody, FN dependent effect on COX expression was not observed. Analysis by ELISA and immunoblotting confirmed FN-dependent upregulation of COX-2 protein. The ratio of PG E(2):PG D(2) was significantly high in cells maintained on FN and on treatment with p38 MAPK inhibitor, the relative level of PG D(2) increased and that of PG E(2) decreased. Concomitant with the modulation of COX-2 and changes in PGs, ECs maintained on FN showed angiogenic response in an alpha(5)beta(1) integrin/p38 MAPK dependent manner as evidenced by the expression of angiogenic markers, CD 31 and E-selectin. These results suggest a FN-alpha(5)beta(1)/FAK/p38 MAPK dependent upregulation of COX-2 causing a shift in the relative levels of PGs in HUVECs which contributes to the angiogenic effect of FN.

COX-2 inhibition decreases VEGF expression and alveolar bone loss during the progression of experimental periodontitis in rats

BACKGROUND

Vascular endothelial growth factor (VEGF) is a macromolecule of importance in inflammation that has been implicated in periodontitis. The aims of this study were to investigate VEGF expression during the progression of periodontal disease and to evaluate the effect of a preferential cyclooxygenase (COX)-2 inhibitor meloxicam on VEGF expression and alveolar bone loss in experimentally induced periodontitis.

METHODS

A total of 120 Wistar rats were randomly separated into groups 1 (control) and 2 (meloxicam, 3 mg/kg/day, intraperitoneally, for 3, 7, 14, or 30 days). Silk ligatures were placed at the gingival margin level of the lower right first molar of all rats. VEGF expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR), Western blot (WB), and immunohistochemical (IHC) analyses. The hemiarcades were processed for histopathologic analysis. RT-PCR and WB results were submitted to analysis of variance, the Tukey test, and Pearson correlation analysis (P <0.05).

RESULTS

A reduction in alveolar bone resorption was observed in the meloxicam-treated group compared to the control group at all periods studied. There was a positive correlation between COX-2 mRNA and VEGF mRNA in the gingival tissues and periodontal disease (R = 0.80; P = 0.026). Meloxicam significantly reduced the increased mRNA VEGF expression in diseased tissues after 14 days of treatment (P = 0.023). Some alterations in VEGF receptor 1 mRNA expression were observed, but these were not statistically significant. VEGF protein expression in WB experiments was significantly higher in diseased sites compared to healthy sites (P <0.05). After 14 days of treatment with meloxicam, an important decrease in VEGF protein expression was detected in diseased tissues (P = 0.08). Qualitative IHC analysis revealed that VEGF protein expression was higher in diseased tissues and decreased in tissues from rats treated with meloxicam.

CONCLUSIONS

The present data suggest an important role for VEGF in the progression of periodontal disease. Systemic therapy with meloxicam can modify the progression of experimentally induced periodontitis in rats by reducing VEGF expression and alveolar bone loss.

Cyclooxygenase-2 in cancer and angiogenesis

Tumor angiogenesis is a process where new blood vessels are formed from preexisting ones, resulting in several pathologies. Solid tumors induce angiogenesis to obtain the required nutrients and oxygen. Otherwise, tumors do not grow beyond 2 to 3 mm in diameter. Cyclooxygenase-2, an inducible enzyme important in inflammation, catalyzes the production of prostanoids from arachidonic acid. Cyclooxygenase-2 plays an important role in several cancer types, including colorectal, gastric, prostate, breast, lung, and endometrial cancer. Besides, cyclooxygenase-2 has been implicated in the progression and angiogenesis of cancers. Cyclooxygenase-2 inhibitors have been used to block angiogenesis and tumor proliferation. In this review, the recent studies related to the role of cyclooxygenase-2 in several cancer types and tumor-induced angiogenesis were compiled.

Inhibitory effect of saikosaponin-d on the angiogenesis of experimental hepatocarcinoma in rats

AIM: To investigate the effect of saikosaponin-d (SSd) on the expressions of cycloxygenase-2 (COX-2), vascular endothelial cell growth factor (VEGF) and CD34 during hepatocellular carcinogenesis induced by diethylinitrosamine (DEN).

METHODS: Ninety male SD rats were randomly divided into 5 groups: control group (n = 10), model group (n = 20) and three treatment groups (n = 20 in each group). Except for the control group, the other groups were administered (ig) with 2 g/L DEN at a dose of 10 mg/kg body weight (5 times/wk for 16 wk). At the same time, the rats in the treatment groups were injected intraperitoneally with SSd at different doses (1.0, 1.5 and 2.0 mg/kg) once per day for 16 wk. The rats were anesthetized and killed at 6, 12, and 16 wk. Hematoxylin and eosin (HE) staining was used to examine the changes of liver pathology and the expression of COX-2, VEGF and CD34 in liver tissues were dynamically monitored by SABC immunohistochemistry.

RESULTS: During 6, 12, and 16 wk of experiment, typical pathological changes such hepatocyte injury, hyperplasia, cirrhosis, and carcinogenesis appeared in the rats of model group. Both the volume and the number of tumors were significantly reduced in 3 SSd treatment groups. Under microscope, the cancer cells in the rats of model group showed polymorphic and abnormal shape. In contrast, the cancer cells in the rats of SSd treatment groups were well differentiated. Immunohistochemistry demonstrated that the expression of COX-2 and VEGF and the value of microvessel density (MVD) in the model group were low in the early stage of carcinogenesis, but they were all remarkably increased in the stage of carcinoma. Whereas, the expression of COX-2 and VEGF and MVD value were all reduced in every stage of carcinogenesis after SSd treatment, especially in the stage of carcinoma after high-dose SSd treatment. There was a highly positive correlation between COX-2 and VEGF expression (r = 0.815, P < 0.01), VEGF expression and MVD value (r = 0.862, P < 0.01) and between COX-2 expression and MVD value (r = 0.726, P < 0.01).

CONCLUSION: SSd has inhibitory effect on the angiogenesis during DEN-induced hepatocarcinogenesis in rats, which may be related to the down-regulation of COX-2 expression and VEGF activity.

Prognostic significance of cyclooxygenase-2 overexpression in glottic cancer

PURPOSE

Cyclooxygenase-2 (COX-2) overexpression has been associated with a poor prognosis in many cancers. However, the role of COX-2 overexpression in head and neck cancers remains undetermined. The objective of this study was to evaluate whether COX-2 is a prognostic factor in glottic cancer.

EXPERIMENTAL DESIGN

This study was part of a phase III placebo-controlled randomized trial evaluating the efficacy of alpha-tocopherol in reducing second primary cancers (SPC) in head and neck cancer patients. Immunohistochemical analyses were conducted on pretreatment biopsies of 301 patients with early-stage glottic cancer treated by radiotherapy. The median value of 50% of positive tumor cells was the cutoff point used to define COX-2 overexpression. Outcomes considered in the statistical analysis were recurrence, SPC, and death. The Cox proportional hazards model was used to estimate the hazard ratios (HR) and their 95% confidence intervals (95% CI).

RESULTS

The HR associated with COX-2 overexpression was 0.94 (95% CI, 0.55-1.62) for recurrence. The HR associated with SPC was 2.63 (95% CI, 1.32-5.23) for the first 3.5 years of follow-up and 0.55 (95% CI, 0.22-1.32) for the following 3.5 years. The HR associated with COX-2 overexpression was 1.57 (95% CI, 1.01-2.45) for overall mortality.

CONCLUSIONS

COX-2 overexpression in glottic cancer was associated with increased overall mortality and an increased risk of SPC during the early follow-up period. Future studies are needed to explain observed effects on SPC. COX-2 expression may prove helpful in defining an individual patient's prognosis.

Prediction of chemosensitivity using multigene analysis in head and neck squamous cell carcinoma

AIMS

The main purpose of the current study was to find predictive biomarkers that can be routinely used for the response to chemotherapy in head and neck squamous cell carcinoma (HNSCC).

METHODS

From this standpoint, we selected the histoculture drug response assay (HDRA) to assess in vitro chemosensitivity, and real-time reverse transcription polymerase chain reaction to investigate the gene expression profile of individual tumors as available predictive biomarkers. Using both surgery and biopsy specimens, we analyzed their gene expression profiles using the 18 markers that we thought were likely predictors of the response to anti-cancer agents.

RESULTS

Statistically significant associations were found between 5-fluorouracil (5-FU) sensitivity in HDRA and HER-2 mRNA expression level (p = 0.0030). Moreover, HER-2 expression was significantly associated with cisplatin sensitivity (p = 0.0089). Cisplatin sensitivity in HDRA was also demonstrated to have a significant association with epidermal growth factor receptor (EGFR) expression in which the group with cisplatin resistance tended to have a higher expression level than the sensitive group (p = 0.0385).

CONCLUSION

HER-2 and EGFR may be possible reliable predictive biomarkers for anti-cancer therapy, and might help in the decision-making process for individual patients with HNSCC.

Prognostic significance of cyclooxygenase-2 and DNA topoisomerase IIalpha expression in oral carcinoma

BACKGROUND

Despite recent advances in the diagnosis and treatment of oral carcinoma, outcomes remain disappointing. The identification of new prognostic factors is necessary to improve survival. To determine the prognostic significance of cyclooxygenase (COX)-2 and DNA topoisomerase (DNA-Topo) IIalpha expression in patients with oral carcinoma, we immunohistochemically examined these enzymes and studied their relation to overall 5-year survival.

METHODS

Surgical specimens were obtained from 160 patients with oral carcinoma, 80 with and 80 without regional lymph node metastasis. The specimens were immunostained for COX-2 and DNA-Topo IIalpha as an index of cell proliferative activity. COX-2 immunoreactivity and clinicopathological data were analyzed, and 5-year survival was calculated by the Kaplan-Meier method.

RESULTS

COX-2 expression in primary lesions was higher in cases with lymph node metastasis than in those without lymph node metastasis. An increase in tumor size was associated with increased COX-2 expression. In most cases with lymph node metastasis, COX-2 expression was higher in metastatic lesions than in primary lesions. As COX-2 expression increased, the DNA-Topo IIalpha labeling index significantly increased and the overall 5-year survival rate decreased.

CONCLUSION

Expression of COX-2 and DNA-Topo IIalpha were related to lymph node metastasis, cell proliferative activity, and overall 5-year survival rate in oral carcinoma. These enzymes may therefore be valuable diagnostic and prognostic indices in oral carcinoma.

The role of apoptosis in therapy and prophylaxis of epithelial tumours by nonsteroidal anti-inflammatory drugs (NSAIDs)

In addition to having anti-inflammatory activities, nonsteroidal anti-inflammatory drugs (NSAIDs) also inhibit neoplastic cell proliferation by inducing apoptosis. Diclofenac is the anti-neoplastic compound in diclofenac 3% gel (Solaraze) used for topical treatment of actinic keratosis (AK). Main target of NSAIDs seems to be the inhibition of cyclo-oxygenase-2 (COX-2), which is overexpressed in several epithelial tumours and catalyses the synthesis of prostaglandins. The precise mechanism of action of diclofenac in cutaneous cells is still unclear, but induction of apoptosis is a key effect of anti-neoplastic drugs, including NSAIDs. In this paper we give an overview of the anti-tumoural activities of NSAIDs with emphasis on induction of apoptosis. Cyclo-oxygenase-2-mediated synthesis of prostaglandin E(2) (PGE(2)) leads to activation of mitogen-activated protein kinase (MAPK), as well as phosphatidylinositol 3-kinase (PI3K)/Akt pathways. Induction of the anti-apoptotic Bcl-2 and Mcl-1, as well as activation of the caspase-8 inhibitor cFLIP have been reported. In addition, altered lipid concentrations in the cytoplasmic membrane may modulate death receptor activities. Downregulation of both the intrinsic mitochondrial and the extrinsic pathways have been reported. Our data demonstrate induced apoptosis and activation of the caspase cascade in three of four cutaneous squamous cell carcinoma (SCC) cell lines, after treatment with diclofenac plus hyaluronic acid and diclofenac alone; one cell line remained nonresponsive. The effects were less pronounced in normal keratinocytes and cytotoxic effects were not seen. Detailed analysis of apoptosis pathways employed by diclofenac in these cells may help to improve therapeutic strategies and to overcome possible mechanisms that are involved in nonresponsiveness.

The prognostic significance of COX-2 and survivin expression in ovarian cancer

We investigated the prognostic significance of cyclooxygenase-2 (COX-2) and survivin in ovarian carcinoma. Imprint smears were obtained from 100 ovarian carcinoma specimens and were studied immunocytochemically for the expression of COX-2 and survivin. The results were correlated with several clinicopathological parameters, including 5-year survival. Increased COX-2 staining pattern correlated with a non-mucinous histological type (p=0.008), increased stage (p<0.0001), high histological grade (p<0.0001), and reduced survival rates (p<0.00001). Survivin expression was strongly associated with increased stage (p<0.0001), increased histological grade (p<0.0001), and reduced survival (p<0.00001). Elevated survivin expression also correlated significantly with pre-menopausal status (p=0.033). In addition, COX-2 and survivin staining patterns correlated strongly with one another (p<0.0001). However, on multivariate analysis, an independent prognostic value was found only for tumor stage and grade. The findings of our study indicate that the increased expression of COX-2 and survivin in ovarian cancer is associated with one another and with several adverse clinicopathologic parameters, including reduced survival, thus suggesting a role of these molecules in disease progression. Further investigations of the exact prognostic and therapeutic implications of COX-2 and survivin expression are strongly warranted.

Selective cyclooxygenase-2 inhibition suppresses basic fibroblast growth factor expression in human esophageal adenocarcinoma

Inhibition of cyclooxygenase (COX)-2 is reported to suppress growth and induce apoptosis in human esophageal adenocarcinoma (EADC) cells, although the precise biologic mechanism is unclear. In this study we tested the hypothesis that the antitumor activity of COX-2 inhibitors may involve modulation of basic fibroblast growth factor (FGF-2), which is overexpressed in EADC. We evaluated the effects of NS-398, a selective COX-2 inhibitor, on FGF-2 expression and proliferation of EADC cell lines that express COX-2 and those that do not. We also correlated COX-2 and FGF-2 expression with clinico-pathologic findings and outcome in a well-characterized series of surgically resected EADC tissues. Seg-1 cells robustly expressed COX-2 and FGF-2, whereas Bic-1 cells expressed neither transcript. FGF-2 was reduced to undetectable levels in Seg-1 cells following NS-398 treatment, but increased within 4 h of drug removal. NS-398 significantly inhibited the growth of Seg-1 cells, and this effect was ameliorated by addition of exogenous FGF-2. In contrast, NS-398 had no effect on Bic-1 cell proliferation and FGF-2 alone had no effect on proliferation of either cell line. NS-398, or a neutralizing anti-FGF-2 antibody, induced apoptosis in Seg-1 cells, and these effects were inhibited by addition of exogenous FGF-2. COX-2 protein was strongly expressed in 46% (10/22) of EADCs, and was associated with a trend towards reduced disease-free survival. These findings indicate that the antitumor effects of COX-2 inhibition in EADC cells may be mediated via suppression of FGF-2, and that COX-2 may be a clinically relevant molecular marker in the management of human EADC.

Expression of cyclooxygenase-2, vascular endothelial growth factor and matrix metalloproteinase-2 in patients with primary laryngeal carcinoma: a tissue microarray study

OBJECTIVE

To determine the correlation between expression of cyclooxygenase-2, vascular endothelial growth factor and matrix metalloproteinase-2, in patients with laryngeal carcinoma.

DESIGN

The study included 85 primary laryngeal squamous cell carcinoma cases. Expression was assessed using Envision immunohistochemical stains for cyclooxygenase-2, vascular endothelial growth factor and matrix metalloproteinase-2.

SUBJECTS

A tissue microarray containing samples from the 85 primary laryngeal squamous cell carcinoma cases was assembled. Immunohistochemical testing for cyclooxygenase-2, vascular endothelial growth factor and matrix metalloproteinase-2 was performed. Using Pearson correlation, expression of these proteins was compared with the following clinicopathological variables: age, sex, clinical tumour-node-metastasis staging, and prognosis. Three-year survival curves, factored by cyclooxygenase-2, vascular endothelial growth factor and matrix metalloproteinase-2 expression, were generated for overall survival, by Kaplan-Meier analysis.

RESULTS

The expression of cyclooxygenase-2 significantly differed between patients with different pathology, tumour-node-metastasis stage and prognosis. A marked difference in vascular endothelial growth factor expression was seen between two histological grade groups. Expression of matrix metalloproteinase-2 protein statistically significantly differed between patients with different tumour-node-metastasis stages, lymph node metastases and three-year survival rates. The expression of cyclooxygenase-2 in laryngeal carcinoma tissue was found to be associated with the expression of matrix metalloproteinase-2.

CONCLUSION

Cyclooxygenase-2 and matrix metalloproteinase-2 may act as clinical prognostic indicators of tumour growth and differentiation in laryngeal carcinoma.

Cyclooxygenase-2 (cox-2) and the inflammogenesis of cancer

Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that aberrant induction of COX-2 and up-regulation of the prostaglandin cascade play a significant role in carcinogenesis, and reciprocally, blockade of the process has strong potential for cancer prevention and therapy. Supporting evidence includes the following: [1] expression of constitutive COX-2-catalyzed prostaglandin biosynthesis is induced by most cancer-causing agents including tobacco smoke and its components (polycylic aromatic amines, heterocyclic amines, nitrosamines), essential polyunsaturated fatty acids (unconjugated linoleic acid), mitogens, growth factors, proinflammatory cytokines, microbial agents, tumor promoters, and other epigenetic factors, [2] COX-2 expression is a characteristic feature of all premalignant neoplasms, [3] COX-2 expression is a characteristic feature of all malignant neoplasms, and expression intensifies with stage at detection and cancer progression and metastasis, [4] all essential features of carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis, and immunosuppression) are linked to COX-2-driven prostaglandin (PGE-2) biosynthesis, [5] animal studies show that COX-2 up-regulation (in the absence of genetic mutations) is sufficient to stimulate the transformation of normal cells to invasive cancer and metastatic disease, [6] non-selective COX-2 inhibitors, such as aspirin and ibuprofen, reduce the risk of human cancer and precancerous lesions, and [7] selective COX-2 inhibitors, such as celecoxib, reduce the risk of human cancer and precancerous lesions at all anatomic sites thus far investigated. Results confirming that COX-2 blockade is effective for both cancer prevention and therapy have been tempered by observations that some COX2 inhibitors pose a risk to the cardiovascular system, and more studies are needed in order to determine if certain of these drugs can be taken at dosages that prevent cancer without increasing cardiovascular risk. It is emphasized that the "inflammogenesis model of cancer" is not mutually exclusive and may in fact be synergistic with the accumulation of somatic mutations in tumor suppressor genes and oncogenes or epigenetic factors in the development of cancer.

Chemoprevention of squamous cell carcinoma of the head and neck

PURPOSE OF REVIEW

The aim of this article is to summarize progress in understanding of the biology of squamous cell carcinoma of the head and neck and of trials to prevent malignant conversion of oral premalignant lesions and the development of second primary tumors in those already treated for squamous cell carcinoma of the head and neck.

RECENT FINDINGS

The understanding of squamous cell carcinoma of the head and neck biology is rapidly evolving. Clinical trials for chemoprevention are involving more diverse regimens, following disappointing results of retinoid monotherapy. In-vitro and animal studies form the rationale for the next generation of studies, employing combination, synergistic treatments.

SUMMARY

Based on trial data to date, no recommendation for intervention with a chemopreventive agent can be made. It is clear, however, that smoking cessation is an effective intervention for preventing oral premalignant lesions and second primary tumors. Promising trials are being conducted and designed currently. The future of this area of study will involve rational choice of multidrug regimens based on current understanding of the biology of squamous cell carcinoma of the head and neck.

Management of actinic cheilitis using diclofenac 3% gel: a report of six cases

BACKGROUND

Actinic cheilitis is a frequent manifestation of actinic dysplasia and requires early therapy to prevent its progression into invasive squamous cell carcinoma (SCC). Several therapies are used, ranging from unspecific lesion-adapted destructive techniques (i.e. laser) to ambitious surgical field-management (vermillionectomy). There is increasing awareness of the effectiveness of field adapted, non destructive therapies, such as photodynamic therapy or 5% imiquimod. Diclofenac 3% gel is used in the treatment of actinic keratosis (AK), but it has not been evaluated for the treatment of actinic cheilitis.

OBJECTIVES

This non-blinded, uncontrolled case series study evaluated the effects of diclofenac 3% gel in the treatment of actinic cheilitis.

PATIENTS/METHODS

Six patients with histologically verified actinic cheilitis were treated with diclofenac 3% gel, twice daily for 6 weeks. Clinical assessment was performed 2-4 weeks after the end of treatment.

RESULTS

Four out of six patients showed clinical clearing of actinic cheilitis 2-4 weeks after the end of treatment. Biopsies were taken from the treated areas at the final visit to verify clinical clearance. Side effects in most of the patients included mild erythema and mild to moderate swelling of the lips.

CONCLUSIONS

Topical therapy with diclofenac 3% gel may be an efficient, cosmetically more appealing alternative treatment for actinic cheilitis than currently used destructive therapies. However, future studies and long-term follow-up of patients will be needed to compare its efficacy with established forms of therapy.

Expression of glycodelin and cyclooxygenase-2 in human endometrial tissue following three-dimensional culture

PROBLEM

Our previous study showed that in vitro culture of human endometrial tissue in a three-dimensional (3D) fibrin matrix could mimic the early stages of endometriosis with invasion, gland and stroma formation and sprouting of new vessels. The objective of the present study was to evaluate the expression of glycodelin (Gd) and cyclooxygenase-2 (COX-2), two angiogenic factors, to further validate the 3D culture model of endometriosis.

METHOD OF STUDY

Human endometrial fragments were obtained from endometrial biopsies and placed in a 3D fibrin matrix culture. Immunohistochemistry with specific antibodies to Gd and COX-2 was used to examine endometrial epithelium and blood vessels, and 4, 6-diamidino-2-phenylindole staining was used for nuclear identification.

RESULTS

Three-dimensional culture of human endometrial tissue in the fibrin matrix resulted in the proliferation of endometrial stromal cells, glandular epithelium and angiogenesis. Gd positive glandular epithelium was seen in 85% of wells with developing endometrial glands and COX-2 positive new vessels were seen in 80% of wells with angiogenesis-like structures after 4 weeks of culture.

CONCLUSION

Our findings confirm that angiogenesis occurs following the culture of endometrial tissue in the 3D fibrin matrix, and suggests that Gd and COX-2 might play important roles in promoting neovascularization and cell proliferation in the establishment of endometriosis.

Cyclooxygenase-2 expression in cervical intraepithelial neoplasia III and squamous cell cervical carcinoma, and its correlation with clinicopathologic variables

The objective of the study was to compare cyclooxygenase-2 (COX-2) expression in cervical intraepithelial neoplasia III (CIN III) and squamous cell carcinoma (SCC) of the cervix, and its correlation with clinicopathologic factors of SCC with a review of the available literature. This study included 25 patients with CIN III and 67 patients with stage I-IIa SCC. All patients in the SCC group were treated with radical hysterectomy plus pelvic and para-aortic lymphadenectomy and postoperative chemoradiotherapy based on their histopathologic risk factors. Immunohistochemical analysis was performed on paraffin-embedded sections with COX-2 antibody. COX-2 expression in the SCC group was significantly higher than in the CIN III group (55.2% [37/67] vs 24% [6/25]; P= 0.008). Significantly higher expression of COX-2 was observed in patients with lymphovascular space invasion (LVSI) compared to patients without LVSI (61.9% [34/55] vs 33.3% [3/9]; P= 0.02). Additionally, patients with tumor sizes >4 cm had significantly higher COX-2 expression than patients with tumor sizes <4 cm (65.9% [27/41] vs 39% [10/26] P= 0.028). There was no significant relationship with respect to COX-2 expression and parametrial involvement, lymph node metastasis, recurrences, and survival. In multivariate analysis, LVSI was the only statistically significant determinant for COX-2 expression (P= 0.024; OR = 2.35; 95% CI = 1.1-4.9). Our results and a review of the literature both suggest that COX-2 expression may have a role in the development and progression of CIN III and it is related to some clinicopathologic variables of cervical carcinoma. Further studies are needed to clarify the role of COX-2 inhibitors in the management of CIN and SCC.

Immunohistochemical evaluation of cyclooxygenase expression in corneal squamous cell carcinoma in horses

OBJECTIVE

To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the cornea, eyelid, and third eyelid of healthy horses and those affected with squamous cell carcinoma (SCC) by use of immunohistochemical techniques.

ANIMALS

15 horses with SCC involving ocular tissues and 5 unaffected control horses.

PROCEDURES

SCC-affected tissues were obtained from the cornea (n = 5 horses), eyelid (5), and third eyelid (5). Site-matched control tissues were obtained from 5 horses unaffected with SCC. Tissue sections of affected and control cornea, eyelid, and third eyelid were stained immunohistochemically for COX-1 and COX-2 via standard techniques. Stain uptake was quantified by use of computer-assisted image analysis of digital photomicrographs.

RESULTS

Immunoreactivity for both COX-1 and COX-2 was significantly greater in equine corneas with SCC than in control corneas. No significant differences in COX-1 or COX-2 immunoreactivity were detected in eyelid and third-eyelid SCC, compared with site-matched control tissues.

CONCLUSIONS AND CLINICAL RELEVANCE

Immunoreactivity for COX-1 and COX-2 is high in equine corneal SCC, possibly indicating that COX plays a role in oncogenesis or progression of this tumor type at this site. Pharmacologic inhibition of COX may represent a useful adjunctive treatment for corneal SCC in horses.

Clinical significance of cyclooxygenase-2 expression in extranodal natural killer (NK)/T-cell lymphoma, nasal type

PURPOSE

To determine whether there are any differences in therapeutic response, patterns of systemic recurrence, and prognosis of patients with extranodal natural killer (NK)/T-cell lymphoma, nasal type, by the cyclooxygenase-2 (COX-2) expression.

PATIENTS AND METHODS

Thirty-four patients with Ann Arbor Stage I and II extranodal NK/T-cell lymphoma who underwent chemotherapy or radiotherapy, or both, were retrospectively reviewed. These patients were divided into two groups according to their immunohistochemical staining for COX-2 expressions: a COX-2-negative group (n = 10 patients) and a COX-2-positive group (n = 24 patients). The treatment response, patterns of treatment failure, and survival data for the patients were compared between the COX-2-positive and negative groups.

RESULTS

There was no significant difference in the clinical profiles between the COX-2-negative and COX-2-positive groups. All patients (100%) in the COX-2-negative group achieved complete response after initial treatment, whereas only 14 patients (58%) in the COX-2-positive group achieved complete response (p = 0.03). Compared with the patients in the COX-2-negative group, those in the COX-2-positive group had a significantly lower 2-year systemic recurrence-free survival rate (100% for the COX-2-negative group vs. 54% for the COX-2-positive group) (p = 0.02) and a decreased 5-year overall survival rate (70% for the COX-2-negative group vs. 32% for the COX-2-positive group) (p = 0.06).

CONCLUSION

Cyclooxygenase-2 expression can serve as a predictive factor for poor treatment response, higher systemic recurrence, and unfavorable prognosis in patients with extranodal NK/T-cell lymphoma, nasal type.

Expression of cyclooxygenase-2 mRNA in peripheral blood of head and neck cancer patients and in healthy controls. A pilot study

CONCLUSIONS

Cyclooxygenase-2 mRNA (COX2) levels are higher in head and neck cancer (HNC) patients than in controls and this correlates with tumor size and outcome. These findings suggest the use of this parameter as a future tumor marker.

OBJECTIVE

We analyzed the expression of COX2 mRNA in peripheral blood cells in HNC patients and in healthy controls and its relationship with outcome and progression-free survival.

MATERIALS AND METHODS

Blood samples were obtained from 41 consecutive HNC patients and 16 healthy controls and analyzed for COX2 mRNA with quantitative real-time polymerase chain reaction and compared with beta-actin as a house-keeping gene.

RESULTS

Treatment consisted of surgery only (4 patients), chemoradiotherapy (18), chemotherapy followed by curative surgery (4) or palliative chemotherapy (15). COX2 mRNA levels were higher in patients with unfavorable outcome (mean 6.8, median 2.06) than those with favorable outcome (mean 1.2, median 1.31) (p=0.062). Both were higher than for healthy controls (mean 0.74, median 0.72; p<0.001). In bulky tumors, the percentage of level over 6 in unfavorable outcome cases was higher than in the favorable outcome cases (p=0.005). In chemotherapy patients with level <or=1 no relapse or progression was observed (n=7), and progression-free survival was significantly better than those with level >1 (n=19) (p=0.0138).

Potential involvement of the cyclooxygenase-2 pathway in hepatocellular carcinoma-associated angiogenesis

Angiogenesis plays a crucial role in tumor development and growth. The present study was carried out to investigate the potential involvement of the cyclooxygenase-2 (Cox-2) pathway in the regulation of angiogenesis in hepatocellular carcinoma (HCC). We inhibited Cox-2 expression in HCC cell line HuH-7 by selective Cox-2 inhibitor (SC-58635) or Cox-2 siRNA. Conditioned media (CMs) from HuH-7 cells were used in angiogenic assays in vitro and in vivo. Compared with CMs from untreated and negative siRNA treated HuH-7 cells, CMs from SC-58635 and Cox-2 siRNA treated HuH-7 dramatically suppressed the proliferation, migration, and differentiation of human umbilical vein endothelial cells (HUVECs) in vitro and neovascularization in vivo. These inhibitory effects could be partially reversed by the addition of exogenous PGE2 to CMs. Furthermore, Cox-2 inhibition by SC-58635 resulted in PGE2 reduction accompanied by the down-regulation of four PGE2 receptor (EP receptor) subtypes. Treatment with SC-58635 led to the down-expression of proangiogenic factors such as VEGF, HGF, FGF2, ANGPT1 and ANGPT2 in HCC. An approximately 78% reduction of VEGF level has been found in the CM from SC-58635 treated HuH-7. Our results suggest an involvement of Cox-2 in the control of HCC-associated angiogenesis. PGE2 as a vital angiogenic factor may act directly on endothelial cells to promote HuH-7-stimulated angiogenic process. Moreover, Cox-2/PGE2/EP/VEGF pathway possibly also contributes to tumor angiogenesis in HCC. This study provides the rationale for clinical studies of Cox-2 inhibitors on the treatment or chemoprevention of HCC.

Vascular endothelial growth factor-A and Poly(A) binding protein-interacting protein 2 expression in human head and neck carcinomas: correlation and prognostic significance

Vascular endothelial growth factor-A (VEGF-A) has been demonstrated to play an important role in tumour angiogenesis and to influence prognosis in many cancers. However its prognostic value in head and neck squamous cell carcinomas (HNSCCs) remains controversial. Therefore, we investigated the clinical relevance of VEGF-A expression in HNSCCs and analysed whether its expression was associated with PAIP2 protein levels, a VEGF-A mRNA-binding partner that strongly regulates VEGF-A expression in tissue culture. We determined the correlation of VEGF-A and PAIP2 protein levels, quantitatively evaluated in tumour tissue homogenates from 54 patients with HNSCC, to clinicopathological parameters. We showed that VEGF-A expression in HNSCC is correlated to the stage of tumour differentiation (P=0.050) and is an independent prognostic factor for progression-free survival (P=0.001) and overall survival (P=0.0004). In a pharynx carcinoma cell line, we demonstrated by RNA interference that VEGF-A expression is closely controlled by PAIP2. Moreover, in human HNSCCs, VEGF-A expression is significantly correlated to PAIP2 protein levels (P=0.0018). Nevertheless, PAIP2 expression is associated with neither clinicopathological factors nor patient's survival. Our data suggest that, in contrast to PAIP2 protein levels, which are unrelated to tumour prognosis, VEGF-A expression could serve as a prognostic marker in head and neck cancer and may be helpful for targeted therapies.

Maspin expression and localization impact on angiogenesis and prognosis in ovarian cancer

INTRODUCTION

The goal of this study is to evaluate the relation of maspin expression and its cellular localization to markers of angiogenesis in epithelial ovarian serous carcinoma (OSC).

MATERIALS AND METHODS

We identified 118 patients with high-grade advanced stage OSC who were treated at our institution. Clinical data were collected, and immunohistochemistry (IHC) with antibodies to VEGF, CD34, COX-2, and maspin was performed on paraffin-embedded tumor blocks. CD34 immunostaining was used to determine microvessel density. The correlation between the various molecular markers was assessed using the Chi-square test. Survival analysis was computed using the Kaplan-Meier model, and various prognostic variables were compared using Cox regression analysis.

RESULTS

Maspin expression was noted in 81.4% (96/118) of tumors. Expression was localized to the nuclear compartment in 21.2% of cases, whereas 60.2% of cases showed evidence of cytoplasmic +/- nuclear expression. Tumors that exhibited nuclear maspin expression had lower VEGF and COX-2 expression than tumors with negative or cytoplasmic expression. Tumors with high nuclear maspin expression had lower mean MVD than those with low or negative expression. The median survival based on localization of maspin was 1146 days for those with negative tumors, 1803 days for those with nuclear maspin, and 637 days for those with cytoplasmic maspin (P < 0.001). In a Cox regression analysis, maspin localization was an independent prognostic factor.

CONCLUSION

Maspin expression and localization seem to play a role in ovarian cancer angiogenesis and progression. High nuclear expression was associated with reduced markers of angiogenesis and prolonged survival.

Relationship between prostaglandin E2 and vascular endothelial growth factor (VEGF) in angiogenesis in human vascular endothelial cells

To address the role of prostaglandin E2 (PGE2) in tube formation of endothelial cells and the relationships between the action of PGE2 and vascular endothelial growth factor (VEGF), cultured human umbilical vein endothelial cells (HUVECs) were used to evaluate tube formation on Matrigel and the expression of angiogenesis-related genes. PGE2 treatment stimulated the tube-like formation of HUVECs. Whereas VEGF-induced tube formation was significantly suppressed by ETYA, an inhibitor of arachidonic acid metabolism, or SU5614, an inhibitor of VEGF-receptor tyrosine kinase, the stimulatory effect of PGE2 was observed in the presence of ETYA or SU5614. Thus, PGE2 counteracted both ETYA- and SU5614-induced blockage of angiogenesis in the presence of VEGF. VEGF induced cyclooxygenase (COX) -2 mRNA expression in HUVECs and increased the PGE2 concentration in the medium. PGE2 treatment enhanced the expression of VEGF mRNA. These findings suggest that PGE2 directly stimulates angiogenesis, apart from VEGF signaling, and further induces VEGF expression in HUVECs. In addition, the effect of VEGF on angiogenesis may be mediated, in part, by PGE2 secretion.

Prevention of head and neck cancer

In the vast majority of cases, head and neck cancer is a preventable disease. The relationship between tobacco and alcohol and these cancers is well established. Despite efforts aimed at reduction of risk factor exposure and early detection methods, head and neck cancer remains one of the more common cancers worldwide. Recent advances in molecular techniques have provided a framework for future targets for early diagnosis and treatment of these malignancies. This review provides a summary of recent developments in primary and secondary prevention of head and neck cancer and innovative strategies aimed at a reduction in incidence and mortality from this disease. The future prevention of head and neck cancer will likely require solutions to the widespread use of tobacco products and innovative diagnostic techniques leading to improvements in overall survival.

The significance of cyclooxygenase-2 expression in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the five most common malignancies in the world and is the second leading cause of death in Hong Kong. Previous studies have shown increased levels of cyclooxygenase-2 (COX-2) in a variety of human malignancies including HCC, suggesting that abnormal COX-2 expression plays an important role in carcinogenesis. In addition, some evidence suggests that selective COX-2 inhibitors suppress the formation of tumors in experimental models. However, there are no data in the literature on using COX-2 as an inhibitor target in HCC. The main objective of this article was to give a brief summary of the recent findings of the role of COX-2 in HCC. We briefly reviewed the significance of COX-2 in varies cancers, and then focused on the recent findings of the significance of COX-2 in HCC. Finally, we further evaluated the possibility of using COX-2 as a therapeutic target in HCC.