Prognostic significance of cyclooxygenase-2 in laryngeal squamous cell carcinoma

Nuclear HER3 expression improves the prognostic stratification of patients with HER1 positive advanced laryngeal squamous cell carcinoma

Background

Compared to the other members of human epidermal growth factor family receptors (HER), the role of HER3 has not been well defined in laryngeal cancer. The predictive and prognostic role of HER3 has been the focus of clinical attention but the research findings are contradictory, especially in laryngeal squamous cell carcinoma (LSCC). The variable localization of HER3 within cancer cells and the role of HER3 in primary and acquired resistance to HER1-targeted therapies remain unclear.

Methods

We performed a retrospective analysis of two cohorts of 66 homogeneous consecutive untreated primary advanced LSCC patients, in which co-expression of HER1, HER2 and HER3 receptors was investigated by semi-quantitative immunohistochemistry. The association of their pattern of expression with survival was evaluated by Kaplan–Meier and Cox’s proportional hazard analyses. Multivariable Cox proportional hazards models were developed to predict median 2- and 3-year RFS and 2.5- and 5-year OS. The Akaike information criterion technique and backwards stepwise procedure were used for model selections. The performance of the final Cox models was assessed with respect to calibration and discrimination.

Results

Immunohistochemical labeling for HER1 and HER2 was localized both in the cell membrane and in the cytoplasm, while HER3 labeling was observed both in the cell cytoplasm and in the nucleus. HER3 expression was inversely correlated with HER1 positivity. The expression patterns of HERs were associated with tumor differentiation. In both cohorts of patients, HER1 expression was associated with reduced relapse-free (RFS) and overall survival (OS). In HER1 positive tumors, the co-expression with nuclear HER3 was associated with better RFS and OS, compared with HER3 negative tumors or tumors expressing HER3 at cytoplasmic level. HER3 expressing tumors had a higher Geminin/MCM7 ratio than HER3 negative ones, regardless of HER1 co-expression. Multivariable analyses identified age at diagnosis, tumor site, HER1, HER3 and age at diagnosis, tumor stage, HER1, HER3, as covariates significantly associated with RFS and OS, respectively. Bootstrapping verified the good fitness of these models for predicting survivals and the optimism-corrected C-indices were 0.76 and 0.77 for RFS and OS, respectively.

Conclusions

Nuclear HER3 expression was strongly associated with favourable prognosis and allows to improve the prognostic stratification of patients with HER1 positive advanced LSCC carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03081-0.

Role of Cyclooxygenase-2 in Head and Neck Tumorigenesis

The cyclooxygenase-2 (COX-2) is a potent enzyme that converts arachidonic acid to prostaglandins (PG), including PGE2, a key mediator of inflammation and angiogenesis. Importantly, COX-2 is activated in response to inflammatory stimuli, where it is also believed to promote the development and progression of head and neck cancers (HNC). COX-2 can mediate its protumorigenic effect through various mechanisms, such as inducing cell proliferation, inhibition of apoptosis, and suppressing the host’s immune response. Furthermore, COX-2 can induce the production of vascular endothelial growth factors, hence, promoting angiogenesis. Indeed, the ability of COX-2 inhibitors to selectively restrict the proliferation of tumor cells and mediating apoptosis provides promising therapeutic targets for cancer patients. Thus, in this comprehensive review, we summarized the reported differential expression patterns of COX-2 in different stages of head and neck carcinogenesis—from potentially premalignant lesions to invasive carcinomas. Furthermore, we examined the available meta-analysis evidence for COX-2 role in the carcinogenesis of HNC. Finally, further understanding of the biological processes of COX-2 and its role in orchestrating cell proliferation, apoptosis, and angiogenesis may give therapeutically beneficial insight to develop the management plan of HNC patients and improve their clinical outcomes.

Expression and clinical implication of cyclooxygenase-2 and E-cadherin in oral squamous cell carcinomas

Epithelial-Mesenchymal Transition (EMT) and angiogenesis are crucial events for development of aggressive and often fatal Oral Squamous Cell Carcinomas (OSCCs). Both promote cancer progression and metastasis development, but while the former induces the loss of E-cadherin expression and, hence cadherin switching; the latter produces hematic blood vessel neo-formation and contribute to OSCC cell growth, tumor mass development, and dissemination. Cyclooxygenase-2 (COX-2) has an important role, not only in angiogenic mechanisms, but also in favoring cancer invasion. Indeed it decreases the expression of E-cadherin and leads to phenotypic changes in epithelial cells (EMT) enhancing their carcinogenic potential. Our aim is to evaluate the interplay between E-cadherin cytoplasmic delocalization, COX-2 up-regulation and COX-2 induced neo-angiogenesis in 120 cases of OSCC. We have analyzed the distribution and the number of neo-formed endothelial buds surrounding infiltrating cells that express COX-2, as well as the neo-formed vessels in chronic inflammatory infiltrate, which surround the tumor. A double immunostaining method was employed in order to verify co-localization of endothelial cell marker (CD34) and COX-2. IHC has also been used to assess E-cadherin expression. Our data demonstrate that the OSCC cells, which lose membranous E-cadherin staining, acquiring a cytoplasmic delocalization, overexpress COX-2. Moreover, we find a new CD34+ vessel formation (sprouting angiogenesis). Only basaloid type of OSCC showes low level of COX-2 expression together with very low level of neo-angiogenesis and consequent tumor necrosis. The well-known anti-metastatic effect of certain COX-2 inhibitors suggests that these molecules might have clinical utility in the management of advanced cancers.

Role of Inflammatory Markers in Prognosis of Oral Squamous Cell Carcinoma

BACKGROUND

This estudie evaluated the immunostaining of cytokines in oral carcinoma, in tissue of margin of surgical resecate (MSR) and metastatic lymph nodes, as well as their role in patient prognosis.

METHODS

A retrospective study was carried out in patients with oral squamous cell carcinomas, and sociodemographic and clinical-pathological data were evaluated. In addition, surgical site analysis of the patients was conducted by immunohistochemistry, using a tissue microarray for inflammatory (Tumor Necrosis Factor-alpha, Interleukin-1beta, Interleukin-6, interleukin-10), transcription NF-kappa B and CD68 markers. Immunoexpression was assessed qualitatively and quantitatively using ImageJ software, and data were correlated with the prognostic factors and patient survival rates.

RESULTS

There was a greater immunoexpression of inflammatory and CD68 cytokines in primary tumour and lymph node metastasis than in MSR. In a multinomial logistic regression model, patients with low education (p = 0.041) and a high histoscore for TNF-α (p = 0.021) showed a survival rate of 15.64 (95% CI = 1.13-217.24) and 6.81 (95% CI = 1.02-105.96).

CONCLUSION

Therefore, despite there is an increased immunoexpression of cytokines in the primary tumour, only TNF-α was the inflammatory cytokine that influenced the survival of patients with oral cancer.

Prognostic and predictive value of EGFR in head and neck squamous cell carcinoma

EGFR is an extensively studied biomarker in head and neck squamous cell carcinoma (HNSCC). In this review, we discuss the prognostic and predictive role of EGFR in HNSCC, focusing on the different molecular alterations in specific treatment modalities such as radiotherapy alone (RT), combination of surgery, RT and chemotherapy (CT), EGFR inhibitors. We considered EGFR at different molecular levels: protein expression, protein activation, gene copy number, polymorphisms, mutation, EGFRvIII expression and EGFR ligand expression.

Considering RT alone, evidence supports the predictive and prognostic role of high EGFR expression only when evaluated by quantitative assays: this may help select the patients who can mostly benefit from accelerated treatment. Conversely, no predictive biomarkers are available when treatment is a combination of surgery, CT and RT. For this combined treatment, several studies indicate that EGFR expression represents a good prognostic parameter only when measured by a “quantitative” or at least semi-quantitative method. With respect to EGFR inhibitors, neither EGFR expression nor increased gene copy number represent prognostic/predictive factors.

If validated, nuclear EGFR, TGFα levels, EGFR phopshorylation and polymorphisms could represent additional prognostic factors in relation to combination of surgery, CT and RT, while EGFR polymorphisms and high amphiregulin levels could have prognostic value in patients treated with EGFR inhibitors.

Clinicopathological and prognostic significance of cyclooxygenase-2 expression in head and neck cancer: A meta-analysis

Several studies have assessed the clinicopathological and prognostic value of cyclooxygenase-2 (COX-2) expression in patients with head and neck cancer (HNC), but their results remain controversial. To address this issue, a meta-analysis was carried out. A total of 29 studies involving 2430 patients were subjected to final analysis. Our results indicated that COX-2 expression was not statistically associated with advanced tumor stage (OR, 1.23; 95% CI, 0.98–1.55) but correlated with high risk of lymph node metastasis (OR, 1.28; 95% CI, 1.03–1.60) and advanced TNM stage (OR, 1.33; 95% CI, 1.06–1.66). Moreover, COX-2 expression had significant effect on poor OS (HR, 1.93; 95% CI, 1.29–2.90), RFS (HR, 2.02; 95% CI, 1.00–4.08) and DFS (HR, 5.14; 95% CI, 2.84–9.31). The results of subgroup analyses revealed that COX-2 expression was related with high possibility of lymph node metastasis in oral cancer (OR, 1.49; 95% CI, 1.01–2.20) and advanced TNM stage in oral cancer (OR, 1.58; 95% CI, 1.05–2.37) and no site-specific HNC (OR, 1.64; 95% CI, 1.02–2.62). However, subgroup analyses only showed a tendency without statistically significant association between COX-2 expression and survival. Significant heterogeneity was not found when analyzing clinicopathological data, but it appeared when considering survival data. No publication bias was detected in this study. This meta-analysis suggested that COX-2 expression could act as a prognostic factor for patients with HNC.

Reduction of p38 mitogen-activated protein kinase and cyclooxygenase-2 signaling by isoflurane inhibits proliferation and apoptosis evasion in human papillomavirus-infected laryngeal papillomas

Human laryngeal papilloma (LP) is a human papillomavirus-induced hyperplastic tumor of the respiratory tract, which is characterized by rapid growth and apoptosis resistance. Isoflurane (ISO) inhibits proliferation and elicits apoptosis in cancer cells. The results of the present study found that the mRNA and protein levels of cyclooxygenase-2 (COX2) were higher in LP tissues than in normal laryngeal samples, and prostaglandin E₂ (PGE₂) production was increased in LP cells, as determined by quantitative polymerase chain reaction, western blot and radioimmunoassay analyses. Notably, the increase in COX2 and PGE₂ levels was significantly abrogated in the ISO-treated LP cells. The inhibitory effects of ISO on COX2 expression and activity depended on the inactivation of p38 mitogen-activated protein kinase (MAPK) in LP cells. By inhibiting the COX2 activity of LP cells, ISO treatment markedly suppressed cell viability and proliferation, as determined using Cell Counting Kit-8, flow cytometry and 5-ethynyl-20-deoxyuridine incorporation assays. Furthermore, ISO treatment promoted cell apoptosis, as demonstrated by flow cytometry, nucleosomal fragmentation and caspase-3 activity assays. Collectively, the present results suggest that COX2 is critical in the progression of LP, and ISO is a potential agent for LP therapy by impeding p38 MAPK/COX2 signaling.

High expression of cyclooxygenase 2 is an indicator of prognosis for patients with esophageal squamous cell carcinoma after Ivor Lewis esophagectomy

BACKGROUND

The poor prognosis of esophageal squamous cell carcinoma (ESCC) is attributed to a high recurrence rate after surgery. Cyclooxygenase 2 (COX2) is an important regulator of cell growth, differentiation, apoptosis, and transformation. COX2 overexpression is significantly associated with the tumorigenesis and progression of diverse cancers; however, its expression and significance in ESCC remains unclear.

METHODS

We enrolled 118 patients with ESCC who had undergone Ivor-Lewis esophagectomy. The expression profile of COX2 was examined by immunohistochemistry.

RESULTS

A high expression of COX2 correlated with a higher T staging (P = 0.014), lower differentiation degree (P = 0.002), lymph node metastasis (P = 0.009), recurrence status (P = 0.004), and tumor node metastasis (TNM) stage (P = 0.001). Cox regression analysis showed that TNM stage (P = 0.001), differentiation degree (P = 0.001), and high COX2 expression (P = 0.004) were independent risk factors of prognosis.

CONCLUSION

Our data indicated that COX2 expression level is associated with key clinicopathological features and could be an effective biomarker to predict ESCC prognosis.

Immunohistochemical expression of cyclooxygenase-2 in patients with advanced cancer of the larynx who have undergone induction chemotherapy with the intention of preserving phonation

INTRODUCTION

Cyclooxygenase-2 (COX2) is an enzyme that plays a role in different stages of the carcinogenic process and has prognostic and predictive values that have not yet been established. The objective of this study was to evaluate the role of COX2 overexpression in advanced squamous cell carcinoma of the larynx that has been treated with a phonation conservation protocol.

MATERIALS AND METHODS

This study included a retrospective analysis of 59 patients with resectable tumours that were treated with chemotherapy (CT) and/or radiation therapy (RT). The expression levels of COX2, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and vascular endothelial growth factor receptor (VEGFR-2) in collected biopsy specimens were determined via immunohistochemistry.

RESULTS

Forty-four percent of the included samples demonstrated overexpression of COX2. In the statistical analysis, COX2 overexpression did not correlate with other clinical or treatment efficacy prognostic factors; however, the median global survival (OS) of patients whose tumours expressed COX2 was 79 months, whereas COX2-negative patients had a median OS of only 38 months, although this finding did not reach statistical significance. The other analysed biological parameters did not demonstrate a significant relationship with COX2.

CONCLUSIONS

COX2 overexpression was a common finding in our study. The results obtained did not reveal relationships with established prognostic categories; however, the difference in survival between patients with and without COX2 expression justifies the need for future prospective studies that utilise a larger patient sample size.

Constitutive overexpression of the oncogene Rac1 in the airway of recurrent respiratory papillomatosis patients is a targetable host-susceptibility factor

Recurrent respiratory papillomatosis (RRP) is caused by human papillomaviruses (HPVs), primarily types 6 and 11. The disease is characterized by multiple recurrences of airway papillomas, resulting in high levels of morbidity and significant mortality. The prevalence of latent HPV in the larynx of the general population is much greater than the prevalence of RRP, suggesting a host-susceptibility factor for disease. We report that the oncogene Rac1 and its downstream product cyclooxygenase-2 (COX-2) are both constitutively expressed at high levels throughout the airway of these patients, independent of active HPV infection. Use of the COX-2 inhibitor celecoxib in primary papilloma cell culture resulted in the downregulation of HPV transcription. Furthermore, a proof-of-principle study treating three patients with severe RRP with celecoxib resulted in remission of disease in all cases. Therefore, we have identified the first pharmacologically targetable host-susceptibility pathway that contributes to RRP recurrence.

Cyclooxygenase-2 expression and clinical parameters in laryngeal squamous cell carcinoma, vocal fold nodule, and laryngeal atypical hyperplasia

BACKGROUND

The diagnostic role of cyclooxygenase-2 (COX-2) expression in laryngeal atypical hyperplasia, vocal fold nodule, and laryngeal squamous cell carcinoma was examined.

METHODS

Specimens obtained from patients diagnosed with vocal fold nodule (n = 35), atypical hyperplasia (n = 35), laryngeal squamous cell carcinoma (n = 35), and clinical parameters were evaluated retrospectively.

RESULTS

Although no staining was observed in patients with vocal fold nodules, staining was noted in laryngeal atypical hyperplasia and squamous cell carcinoma. The percentage of COX-2 staining was the highest in the carcinoma group.

CONCLUSION

It was determined that COX-2 staining was significantly associated with laryngeal squamous cell carcinoma. It should be noted that overexpression of COX-2, a potentially important factor in the evolution of carcinogenesis in precancerous lesions, might be an indicator of the development of carcinoma.

Prognostic significance of cyclooxygenase-2, epidermal growth factor receptor 1, and microvascular density in gastric cancer

Gastric cancer remains a significant global health burden with poor treatment outcome. New treatment modalities that target inflammation, proliferation, and angiogenesis have been used in various cancers, including gastric cancer. We sought to study the pattern of expression of two important proteins, cyclooxygenase-2 and epidermal growth factor receptor, and their association with microvascular density, clinicopathological features, and survival in Arab Omani patients with gastric cancer. Formalin-fixed, paraffin-embedded tumors were studied by immunohistochemistry using monoclonal antibodies to cyclooxygenase-2, epidermal growth factor receptor, and CD34. The immunohistochemical results were correlated with clinicopathological features and survival. In our study population, we found a male/female ratio of 72:43, a median age of 59 years, stage III and IV incidence of 66.9%, and a median follow-up of 96 months. Positive expression rates of cyclooxygenase-2 and epidermal growth factor receptor were 89.6 and 23.5%, respectively. The median microvascular density value was 52.5. When this value was determined as the cut-off point, 50% of patients were found to have high microvascular density. Epidermal growth factor receptor over-expression correlated with high microvascular density values, advanced lymph node involvement (N3), and TNM stage presentation (III and IV). Similarly, lymph node involvement was associated with cyclooxygenase-2 over-expression and high microvascular density. Univariate analysis showed that epidermal growth factor receptor over-expression, pathological T3 and T4 disease, and overall stage III and IV disease were adverse prognostic factors. On multivariate analysis using a Cox regression model, expression of epidermal growth factor receptor, and advanced TNM stage were significant adverse prognostic factors for overall survival. Expression of epidermal growth factor receptor in Arab Omani patients with gastric cancer correlates with aggressive tumor characteristics and is an independent prognostic factor. Further clinical studies are needed to evaluate the utility of epidermal growth factor receptor immunohistochemistry as a tool for gastric cancer treatment.

Cyclooxygenase-2 expression in oral tongue squamous cell carcinoma

BACKGROUND

Cyclooxygenase-2 expression is associated with unfavorable outcome in various cancers, and evidence is accumulating that carcinogenesis possibly evolves from intracellular changes in response to induction of this enzyme. Today selective cyclooxygenase-2 inhibitors are being studied and used as complement in cancer treatment. This study examined the prognostic value of cyclooxygenase-2 expression in oral tongue squamous cell carcinoma (OTSCC).

METHODS

Expression of cyclooxygenase-2 was determined in biopsies from 76 stage matched patients with OTSCC by immunohistochemistry between January 2000 and December 2004 in Stockholm, Sweden. Additionally, twelve samples taken after pre-operative radiotherapy were investigated.

RESULTS

All OTSCC specimen expressed cyclooxygenase-2 by immunostaining. The cyclooxygenase-2 staining intensity increased significantly with more advanced stage (P=0.020). Fifty percent of the surgical specimen showed a decrease in immunostaining post-radiation (P=0.031). No association was found with survival.

CONCLUSION

Cyclooxygenase-2 expression has limited prognostic value in OTSCC.

Docosahexaenoic acid reverts resistance to UV-induced apoptosis in human keratinocytes: involvement of COX-2 and HuR

The dramatic increase in the incidence of nonmelanoma skin cancer over the last decades has been related to the augmented exposure to ultraviolet (UV) radiation (UVR). It is known that apoptosis is induced as a protective mechanism after the acute irradiation of keratinocytes, whereas apoptotic resistance and carcinogenesis may follow the chronic exposure to UVR. We found that not all the human keratinocytes lines studied underwent apoptosis following acute exposure to UVR (10-60 mJ/cm(2)). Whereas UVR induced apoptosis in the HaCaT cells, NCTC 2544 and nr-HaCaT cells showed apoptosis resistance. The cytokeratin pattern of the apoptosis-resistant cells indicated that they possessed a degree of differentiation lower than that of HaCaT cells. They also showed an enhanced expression of cyclooxygenase-2 (COX-2), an early marker of carcinogenesis in various tissues, including skin. n-3 polyunsaturated fatty acids have drawn increasing interest as nutritional factors with the potential to reduce UVR carcinogenesis, and since they are apoptosis inducers and COX-2 inhibitors in cancer cells, we investigated the ability of n-3 polyunsaturated fatty acids to influence the resistance to UVR-induced apoptosis in keratinocytes. We observed that docosahexaenoic acid (DHA) reverted the resistance of nr-HaCaT cells to UVR-induced apoptosis, increasing the Bax/Bcl-2 ratio and caspase-3 activity, and reduced COX-2 levels by inhibiting the expression of the human antigen R (HuR), a known COX-2 mRNA stabilizer in keratinocytes. The transfection of nr-HaCaT cells with HuR siRNA mimicked the proapoptotic effect of DHA. Overall, our findings further support the role of DHA as a suitable anticarcinogenic factor against nonmelanoma skin cancers.

Epidermal growth factor receptor protein expression and gene amplification in normal, hyperplastic, and cancerous glottic tissue: immunohistochemical and fluorescent in situ hybridization study on tissue microarrays

AIM

To evaluate the importance of epidermal growth factor receptor (EGFR) protein overexpression and gene amplification in carcinogenesis of glottic cancer.

METHOD

In order to evaluate EGFR expression at protein and gene level, immunohistochemical (IHC) analysis and fluorescent in situ hybridization (FISH) were performed on tissue microarrays of laryngeal tissue (145 samples) -- 38 samples of normal mucosa, 46 samples of hyperplastic lesions, and 61 samples of cancerous lesions.

RESULTS

Membranous (mEGFR) and cytoplasmic (cEGFR) EGFR expression was significantly different between the analyzed groups. The differences were most striking in the suprabasal-transforming zone. IHC evaluation showed that high and low mEGFR staining contributed to the differentiation of dysplastic lesions, simple hyperplasia, and cancerous tissue, as well as between different degrees of atypia in hyperplastic lesions (P<0.050). EGFR gene amplification was not found in simple and abnormal hyperplastic lesions, but it was confirmed in 2/21 atypical hyperplasias, indicating that gene amplification can facilitate identification of malignant potential in hyperplastic lesions. In cancerous tissue, EGFR gene amplification was found in 8/50 samples. EGFR gene amplification was found in preinvasive cancer in one patient. In invasive carcinomas, gene amplification was not associated with stage or grade. Carcinomas with gene amplification showed significantly higher cEGFR expression (basal layer P=0.003; suprabasal layer P=0.002).

CONCLUSIONS

This study confirmed an increase in EGFR protein expression and gene amplification with the increase in biological aggressiveness of glottic lesions. A correlation between EGFR gene amplification and protein expression was established. Gene amplification proved to be an early event in glottic carcinogenesis, indicating its importance for glottic cancer prevention, early detection, and protocol selection.

Parathyroid hormone-related peptide and parathyroid hormone-related peptide receptor type 1 expression in human lung adenocarcinoma

BACKGROUND

In many primary tumors, parathyroid hormone-related peptide (PTHrP) and PTHrP type 1 receptor (PTH1R) are coexpressed, supporting the possibility that PTHrP/PTH1R system can mediate important signals for tumor progression through paracrine/autocrine mechanisms. In non-small cell lung carcinoma the clinical relevance of the expression of PTH1R remains to be investigated.

METHODS

Fifty-four lung adenocarcinomas of mixed histologic type from patients with stage I and II cancer were assayed by quantitative immunohistochemistry for the expression of PTHrP and PTH1R.

RESULTS

PTHrP and PTH1R were expressed in a wide range of intensity in the cytoplasm of tumor cells, and their values showed a positive correlation. PTH1R, but not PTHrP, was expressed by plasma cells infiltrating the tumor stroma. PTHrP and PTH1R were not associated with age, tumor diameter, or histopathologic grading, whereas they were directly associated with lymph node involvement at presentation. Cox regression analysis, using PTHrP and PTH1R as continuous covariates, showed that the covariate levels were directly associated with the risk of death and metastasis. Patients whose tumors coexpressed high levels of PTHrP and PTH1R showed the highest risk of metastasis (relative risk, 5.89; 95% CI, 2.1-16.6; P = .0003) and death (relative risk, 6.24; 95% CI, 1.6-23.9; P = .0033). The presence of PTH1R-positive plasma cells in the tumor stroma was associated with a more favorable survival rate independently from the PTHrP status of the tumor.

CONCLUSION

The paracrine/autocrine signaling through PTHrP/PTH1R could be important in early-stage lung adenocarcinoma progression.

shRNA-targeted cyclooxygenase (COX)-2 inhibits proliferation, reduces invasion and enhances chemosensitivity in laryngeal carcinoma cells

Cyclooxygenase-2 (COX-2), one isoform of cyclooxygenase proinflammatary enzymes, is a causal factor for tumor development, invasion, metastasis, and chemoresistance. It is frequently overexpressed in a variety of human malignancies, including laryngeal carcinoma. To investigate its possibility as a therapeutic target for the treatment of laryngeal carcinoma, we employed RNA interference technology to downregulate endogenous gene COX-2 expression in laryngeal carcinoma cells and analyzed its phenotypical changes. Results showed that shRNA-mediated downregulation of COX-2 expression in human laryngeal carcinoma cells significantly inhibited cell proliferation and colony formation in vitro and reduced the potential of tumorigenicity in vivo. The specific downregulation led to cell arrest in the G(0)/G(1) phase of cell cycle and final apoptosis induction. The increased apoptosis was associated with the ratios of Bcl-2 or Bcl-xL/Bax. In the present study, we also observed that the downregulation of COX-2 could obviously enhanced the cytotoxic effect of Taxanes both in vitro and in vivo. All these results suggest that knockdown of COX-2 expression can lead to potent antitumor activity and chemosensitizing activity to taxanes in human laryngeal carcinomas.

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.

Rationale for adjuvant fatty acid therapy to prevent radiotherapy failure and tumor recurrence during early laryngeal squamous cell carcinoma

Information from a preceding lipid study contributed to the pathobiological assessment of laryngeal squamous cell carcinoma (LSCC). Lipid-driven signaling pathways are responsible for laryngeal carcinogenesis and immunodeficiency. The construction of fatty acid (FA) profiles for LSCC allowed the identification of FA role players. The integration of lipid and clinicomolecular information encountered in the literature, in turn, allowed the identification of biological prognostic markers to distinguish between early (less aggressive) and advanced (more aggressive) LSCCs. High arachidonic acid (AA) and cyclooxygenase (COX-2) activities are criteria for less aggressive growth, whilst low AA and COX-2 activities occur during more aggressive growth. Excessive tobacco use and environmental smoke or human papillomavirus (HPV) infection and alcohol abuse can, respectively, elicit cumulative oxidative stress and an oxidative burst or interfere with signaling pathways during essential fatty acid (EFA) metabolism, all factors and events which may cause LSCC. Research revealed that enhanced COX-2 activity and Bcl-2 expression prevent apoptosis and, hence, LSCCs become resistant to radiotherapy. It was also observed that recurrent laryngeal cancers become more aggressive after radiotherapy failure. It is predicted that manipulation of AA activity and consequently a cascade of downstream factors that include COX-2 and Bcl-2 expression responsible for LSCC may have therapeutic potential to improve radiotherapy outcome during early LSCC. Adjuvant FA therapy to improve early LSCC management by counteracting radiotherapy failure and unwanted complications for further management is proposed. FA therapeutic strategies before and during radiotherapeutic courses need to be evaluated.

Expansion of human T regulatory type 1 cells in the microenvironment of cyclooxygenase 2 overexpressing head and neck squamous cell carcinoma

Cyclooxygenase 2 (COX-2) overexpression and production of prostaglandin E(2) (PGE(2)) by head and neck squamous cell carcinomas (HNSCC) induce type 1 regulatory T (Tr1) cells and contribute to carcinogenesis by creating a tolerogenic milieu. To test this hypothesis, CD4(+)CD25(-) T cells obtained from the peripheral blood of 10 normal donors were cocultured with autologous dendritic cells, irradiated HNSCC cells and cytokines, interleukin 2 (IL-2), IL-10, and IL-15. HNSCC cells were either COX-2 negative, constitutively expressed COX-2, were transfected with COX-2, or had COX-2 expression knocked down by small interfering RNA. Other modifications included coculture plus or minus the COX-inhibitor, Diclofenac, or synthetic PGE(2) in the absence of HNSCC. Lymphocytes proliferating in 10-day cocultures were phenotyped by flow cytometry, studied for cytokine production by ELISA and for suppressor function in CFSE inhibition assays plus or minus anti-IL-10 or anti-transforming growth factor-beta(1) (TGF-beta(1)) monoclonal antibodies (mAb). COX-2(+) HNSCC or exogenous PGE(2) induced outgrowth of Tr1 cells with the CD3(+)CD4(+)CD25(-)IL2Rbeta(+)IL2Rgamma(+)FoxP3(+)CTLA-4(+)IL-10(+)TGF-beta(1)(+)IL-4(-) phenotype and high suppressor functions (range, 46-68%). Small interfering RNA knockout of COX-2 gene in HNSCC led to outgrowth of lymphocytes with decreased IL2Rgamma (P = 0.0001), FoxP3 (P = 0.05), and IL-10 (P = 0.035) expression and low suppressor activity (range, 26-34%). Whereas COX-2(+) cocultures contained IL-10 and TGF-beta(1) (medians, 615 and 824 pg/mL), cytokine levels were decreased (P < 0.0001) in COX-2(-) cocultures. Inhibition of COX-2 enzymatic activity in HNSCC abrogated outgrowth of Tr1 cells. Neutralizing mAbs to IL-10 and/or TGF-beta(1) abolished Tr1-mediated suppression. COX-2 overexpression in HNSCC plays a major role in the induction of Tr1 cells in the tumor microenvironment.

Non-steroidal anti-inflammatory drugs to potentiate chemotherapy effects: from lab to clinic

Most solid tumors express the cyclooxygenase-2 (COX-2) protein, a target of NSAIDs. COX-2 overexpression in tumorsis considered a predictor of more advanced stage disease and of worse prognosis in a number of studies investigating solid malignancies. Therefore, NSAIDs are evaluated as anti-cancer drugs. NSAIDs inhibit proliferation, invasiveness of tumors, and angiogenesis and overcome apoptosis resistance in a COX-2 dependent and independent manner. This review will focus on the rationale behind NSAIDs, including selective COX-2 inhibitors, in combination with conventional chemotherapeutic drugs or novel molecular targeted drugs. Studies investigating anti-cancer effects of NSAIDs on cell lines and xenograft models have shown modulation of the Akt, NF-kappaB, tyrosine kinase and the death receptor-mediated apoptosis pathways. COX-2 expression in tumors is not yet used as biomarker in the clinic. Despite the increased risk on cardiovascular toxicity induced by selective COX-2 inhibitors, several ongoing clinical trials are still investigating the therapeutic benefits of NSAIDs in oncology. The anti-tumor effects in these trials balanced with the side effects data will define the precise role of selective COX-2 inhibitors in the treatment of cancer patients.

Simultaneous expression of cyclooxygenase-2 and microsomal prostaglandin E synthase in squamous cell carcinoma of the larynx

CONCLUSION

In laryngeal cancer, arachidonic acid may be metabolized to PGE2 via the cooperative actions of COX-2 and mPGES, which are induced in response to various stimuli. The COX-2-mPGES-PGE2 system may induce differentiation of cancer cells and prevent metastasis, thus improving the survival rate.

OBJECTIVE

To examine the expression of COX-1, COX-2, and two downstream enzymes--microsomal PGE synthase (mPGES) and PGD synthase (PGDS)--using immunohistochemistry in human laryngeal squamous cell carcinoma (SCC).

PATIENTS AND METHODS

Patients with laryngeal carcinoma were referred to the Department of Otolaryngology for treatment. Formalin-fixed, paraffin-embedded laryngeal carcinoma specimens were obtained from 24 patients. Immunohistochemical expression of COX-1, COX-2, mPGES, LPGDS, and HPGDS was investigated in 24 laryngeal carcinoma samples.

RESULTS

Among the carcinomas, cytoplasmic immunoreactivity for COX-2 was found in tumor cells in 18 of 24 cases (72%) and that for mPGES in tumor cells in 23 of 24 cases (92%). The localization of mPGES was very similar to that of COX-2. COX-2 in well-differentiated SCCs was higher than in poorly/moderately differentiated SCCs. In terms of lymph node metastasis, there was a significant difference in COX-2 expression.

Cyclooxygenase-2 and epithelial growth factor receptor up-regulation during progression of Barrett’s esophagus to adenocarcinoma

AIM: To investigate the expression of cyclooxygenase-2 (COX-2) and epithelial growth factor receptor (EGFR) throughout the progression of Barrett’s esophagus (BE).

METHODS: COX-2 and EGFR protein expressions were detected by using immunohistochemical method. A detailed cytomorphological changes were determined. Areas of COX-2 and EGFR expression were quantified by using computer Imaging System.

RESULTS: The expressions of both COX-2 and EGFR increased along with the progression from BE to esophagus adenocarcinoma (EAC). A positive correlation was found between COX-2 expression and EGFR expression.

CONCLUSION: COX-2 and EGFR may be cooperative in the stepwise progression from BE to EAC, thereby leading to carcinogenesis.

Molecular predictors of clinical outcome in patients with head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) involves the upper aerodigestive tract and can destroy the structure and function of organs involved in voice, speech, taste, smell and hearing, as well as vital structures necessary for survival. HNSCC has long been a treatment challenge because of the high rate of recurrences and of advanced disease at the time of diagnosis. Molecular identification of tissue biomarkers in diagnostic biopsy specimens may not only identify patients at risk for developing HNSCC but may also select patients that may benefit from more aggressive treatment modalities. Several biomarkers studied to date such as the proteins p53, cyclin D1, p16, Cox-2 enzyme, epidermal growth factor and vascular endothelial growth factor receptors, matrix metalloproteinases and the Fhit marker for genomic instability could be manipulated for the therapeutic benefit of these patients. This review presents the most updated information on molecular biomarkers with the greatest prognostic potential in HNSCC and discusses some factors that contribute to the controversy concerning their prognostic importance.

Epidermal growth factor-induced cyclooxygenase-2 expression is mediated through phosphatidylinositol-3 kinase, not mitogen-activated protein/extracellular signal-regulated kinase kinase, in recurrent respiratory papillomas

PURPOSE

Recurrent respiratory papillomas, caused by human papillomaviruses, are premalignant tumors that overexpress the epidermal growth factor receptor (EGFR). The goals of this study were as follows: (a) to evaluate the expression of cyclooxygenase-2 (COX-2) in papillomas, (b) to investigate the role of EGFR signaling in COX-2 expression, and (c) to determine whether COX-2 activity is important for the growth of papilloma cells.

EXPERIMENTAL DESIGN

Immunohistochemistry, Western blotting, and real-time PCR were used to determine levels of COX-2 in papilloma and normal laryngeal tissue. Explant cultures of both normal laryngeal and papilloma cells were used to define the signaling pathways that regulate COX-2 expression and investigate the potential of targeting COX-2 as a strategy to suppress papilloma growth.

RESULTS

COX-2 levels were markedly increased in papillomas. In vitro studies suggested that overexpression in papillomas reflected activation of EGFR-->phosphatidylinositol 3-kinase signaling. Treatment with prostaglandin E2 (PGE2) induced COX-2, whereas celecoxib, a selective COX-2 inhibitor, suppressed levels of COX-2, suggesting a positive feedback loop. Moreover, treatment with PGE2 stimulated papilloma cell growth, whereas celecoxib suppressed proliferation and induced apoptosis.

CONCLUSIONS

Overexpression of COX-2 in papillomas seems to be a consequence of enhanced EGFR-->phosphatidylinositol 3-kinase signaling. We propose a positive feedback loop for COX-2 expression, with induction of COX-2 resulting in enhanced PGE2 synthesis and further expression of COX-2 that contributes to the growth of papillomas in vivo. These data strengthen the rationale for evaluating whether nonsteroidal anti-inflammatory drugs, prototypic COX inhibitors, will be useful in the management of respiratory papillomas.

Molecular markers in laryngeal squamous cell carcinoma: towards an integrated clinicobiological approach

Of the most frequent malignancies in the United States, cancers of the larynx and of the uterine corpus are the only ones not to show an increase in 5-year survival rates over the last 30 years. The increasing use of chemo- and radiotherapy and conservative surgery to preserve organs and their functions has probably led to a better quality of life in patients with laryngeal cancer, but has definitely failed to improve survival, which remains the primary aim. In our opinion, to reduce laryngeal cancer-related mortality, a change in clinical approach is required. We have reviewed the literature on the potential role of molecular markers in the clinical management of laryngeal cancer. We believe that some of the most significant biological markers might be integrated with the evaluation of behavioural risk factors, clinical TNM staging and histopathological grading for a novel clinicomolecular approach to laryngeal cancer. We foresee the use of the most promising biological markers in the phases of prevention, diagnosis, prognostic assessment and drug design.

Increased PGE2 levels in nonmalignant mucosa adjacent to squamous cell carcinoma of the head and neck

OBJECTIVE

The cyclooxygenases (COX) 1 and 2 are the rate-limiting enzymes of prostaglandin E(2) (PGE(2)) synthesis, and the upregulation of COX-2 has been reported in tumors of different origins. The aim of our study was to quantify the PGE(2) expression in squamous cell carcinoma and surrounding mucosa, to analyze the potential of acetylsalicylic acid (ASA) for reducing PGE(2) levels in these tissues, and to improve our understanding of potential tumor-derived stimulation of surrounding mucosa by PGE(2).

STUDY DESIGN AND SETTING

Intracellular PGE(2) levels in primary head and neck squamous cell carcinoma (HNSCC) and the surrounding mucosa at 1 and 2 cm distance were analyzed ex vivo by ELISA. Subsequently, we treated in vitro tumor and normal mucosal cells from turbinates with recombinant PGE(2) and ASA, and quantified intracellular PGE(2) levels.

RESULTS

We observed high PGE(2) levels in the tumor samples and in tumor-surrounding mucosa. The addition of PGE(2) and arachidonic acid to tumor cell cultures resulted in no further increase in intracellular PGE(2) levels, while ASA reduced PGE(2) levels by up to 40%. In normal epithelial cell cultures, less PGE(2) (6% of that found in the tumor cells) was expressed, but stimulation with PGE(2) resulted in levels comparable to those of the tumor samples.

CONCLUSION AND SIGNIFICANCE

We conclude that HNSCC and the surrounding mucosa express high levels of PGE(2). This expression is reduced efficiently by ASA. We propose a stimulation of PGE(2) expression in the epithelium surrounding HNSCC by tumor-derived PGE(2) with a potential impact on tumor growth.

Cyclooxygenase-2 protein levels are independent of epidermal growth factor receptor expression or activation in operable non-small cell lung cancer

Both cyclooxygenase (COX)-2 and epidermal growth factor receptor (EGFR) are thought to play important roles in the pathogenesis of non-small cell lung cancer (NSCLC). A number of in vitro studies have postulated a link between EGFR activation and subsequent COX-2 upregulation. The relationship between these factors has not been established in patients with NSCLC. COX-2 and EGFR expression were studied in 172 NSCLC specimens using standard immunohistochemical techniques. Western blotting was used to determine COX-2 and EGFR levels in five NSCLC cell lines. The effect of treatment with EGF on COX-2 expression in A549 cells was assessed.

RESULTS

Both EGFR and COX-2 are overexpressed in NSCLC. The predominant pattern of COX-2 and EGFR staining was cytoplasmic. Membranous EGFR staining was seen in 23.3% of cases. There was no relationship between COX-2 and EGFR expression and survival or any clinicopathological features. No correlation was seen between EGFR expression and COX-2 expression in the immunohistochemical series or in the cell lines. Treatment with EGF did not upregulate COX-2 levels in A549 cells, either in serum free or serum-supplemented conditions.

CONCLUSIONS

Although COX-2 and EGFR are over-expressed in NSCLC neither was of prognostic significance in this series of cases. There is no correlation between these two factors in either tumour samples or cell lines. Although these factors show no correlation in NSCLC, they remain potential, though independent targets for treatment.

Significance of immunohistochemical expression of cyclooxygenase-2 in squamous cell carcinoma of the esophagus

BACKGROUND

The focus of studies on cyclooxygenase-2 (COX-2) have been on its ability to mediate the biological behavior of human tumors including tumorigenesis, tumor progression, apoptosis, and differentiation. The aim of the current study was to elucidate a further finding on the clinicopathologic significance of immunohistochemical expression of COX-2 in esophageal squamous cell carcinoma (ESCC).

METHODS

The immunohistochemical expression of COX-2 was examined for 76 specimens of ESCC and the correlation of COX-2 expression with clinicopathologic features was examined.

RESULTS

Twenty-eight ESCCs (36.8%) had a strong expression of COX-2. The proportion of poorly differentiated SCCs among tumors with a strong expression of COX-2 (42.8%, 12 of 28) was significantly higher than that among tumors with a weak expression of COX-2 (16.7%, 8 of 48; P = .037). The depth of the tumors (P = .003) and the stage of the tumors (P = .015) were advanced significantly more progressively in ESCCs with a strong COX-2 expression. Univariate analysis showed that the prognosis of patients with ESCCs with a strong COX-2 expression was significantly poorer than that of patients with ESCCs with a weak COX-2 expression (P = .017). Multivariate analysis showed that only such tumor-related factors as lymphatic invasion (P = .004), venous invasion (P = .003), and stage of the tumors (P = .021) were found to be associated independently with worse prognosis of the patients with ESCC.

CONCLUSIONS

Strong expression of COX-2 is correlated with tumor progression and poor differentiation in ESCC.

Cyclooxygenase-2 expression in oral squamous cell carcinoma

Cyclooxygenase (COX), the key enzyme in prostaglandin cascade, is expressed in two isoforms: the constitutive COX-1 and the inducible COX-2. Hyper-expression of COX-2 has been implicated in the pathogenesis of colon-rectal cancer in humans but it appears to play a significant role as a tumour progression factor also in other forms of human cancer, including oral cancer. The aim of this study was to analyze the expression of COX-2, at the protein level, in 45 cases of oral squamous cell carcinoma. Standard immunohistochemical streptavidin-biotin peroxidase analysis was carried out with highly specific antibody against human COX-2 and cell specific markers, in 45 oral squamous cell carcinomas. Our study revealed a moderate to high COX-2 expression in 35 out of the 45 oral squamous cell carcinoma specimens (77.8%). COX-2 expression appeared particularly abundant in the superficial ulcerated layers of relatively well differentiated carcinomas. However, we were unable to assess any statistically significant association between COX-2 hyper-expression and tumor site, tumor grading, tumor size, presence of lymph node metastases, tumor stage and age at onset, respectively. Interestingly, COX-2 expression was detected not only in areas of epithelial dysplasia adjacent to the primary layers (86% of the cases) but also in normal-appearing epithelium at the boundaries of squamous cell carcinoma (77%), indicating a possible involvement in tumour progression by the apparently normal tissue surrounding the lesion. Moreover, intense COX-2 staining was observed in endothelial cells of intra-tumour vessels and extra-tumour vessels adjacent to the tumour nests, in a high proportion of cases (82%). COX-2 positivity was associated with CD34 and VEGF positivity, indicating that these vessels were probably neo-formed ones. From this study as well as from other works, it appears that indeed COX-2 is over-expressed in this important human malignancy. However, further studies are necessary to understand the exact magnitude of this over-expression and, mostly, the possible role of COX-2 in the pathogenesis and progression of oral cancer.

Synchronous coexpression of epidermal growth factor receptor and cyclooxygenase-2 in carcinomas of the uterine cervix: a potential predictor of poor survival

PURPOSE

To evaluate the potential of the new prognostic information gained by analyzing the coexpression of epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) in cervical cancer patients.

EXPERIMENTAL DESIGN

Sixty-eight patients with International Federation of Gynecology and Obstetrics stage IIB squamous cell carcinoma of the uterine cervix, who underwent concurrent chemoradiotherapy between 1993 and 1996, were divided into the following four groups according to their immunoreactivities for EGFR and COX-2 in paraffin-embedded sections: (a). the EGFR-negative/COX-2-negative group (n = 11); (b). the EGFR-negative/COX-2-positive group (n = 8); (c). the EGFR-positive/COX-2-negative group (n = 27); and (d). the EGFR-positive/COX-2-positive group (n = 22). The clinical features, patterns of treatment failure, and survival data in the four groups were compared.

RESULTS

Positive immunoreactivity for EGFR and COX-2 was observed in 49 of 68 (72%) and 19 of 68 (28%), respectively. However, no strong correlation was found between the levels of EGFR and COX-2 immunopositivity (R(2) = 0.05, P = 0.07). Patients in the EGFR-positive/COX-2-positive group had a higher likelihood of locoregional recurrence than those in the other three groups (P = 0.02). Of the patients in the four groups, patients positive for both oncoproteins were found to have the worst prognosis with an overall 5-year disease-free survival rate of 55% compared with 91% for the EGFR-negative/COX-2-negative patients, 88% for the EGFR-negative/COX-2-positive patients, and 69% for the EGFR-positive/COX-2-negative patients (P = 0.05, log-rank test). In addition, the synchronous coexpression of the EGFR and COX-2 oncoproteins was found to be an independent prognostic factor by univariate and multivariate analyses (relative risk = 4.0, P = 0.03).

CONCLUSIONS

Given these observations, we conclude that the coexpression of EGFR and COX-2 immunoreactivity may be used as a potent molecular risk factor for predicting the poor survival of patients with the International Federation of Gynecology and Obstetrics stage IIB squamous cell carcinoma of the uterine cervix.

Prognostic significance of cyclooxygenase-2 in oropharyngeal squamous cell carcinoma

PURPOSE

To determine the relative prognostic significance of cyclooxygenase (COX)-2 expression in patients with oropharyngeal squamous cell carcinoma (SCC).

EXPERIMENTAL DESIGN

This retrospective cohort study included 82 patients with SCC referred to the Department of Therapeutic Radiology at Yale-New Haven Hospital (Connecticut) between 1980 and 1999 who were treated with primary external beam radiotherapy or gross total surgical resection and postoperative radiotherapy. A microarray of archival tumor tissue was constructed and stained with monoclonal antibodies directed against COX-2 and scored for intensity by a pathologist blinded to the clinical outcomes of the patients. COX-2 immunoreactivity and clinicopathological data were analyzed with respect to survival endpoints using bivariate and multivariate techniques.

RESULTS

Frequency of COX-2 overexpression was 45%. In multivariate analysis, COX-2 positivity predicted poor 3-year survival (P = 0.02; odds ratio = 0.41; 95% confidence interval, 0.20-0.84). Increasing age was significantly associated with increased 3-year survival (P = 0.03; odds ratio = 1.04; 95% confidence interval, 1.004-1.09). Positive COX-2 status trended toward predicting decreased 3-year disease-free survival.

CONCLUSIONS

COX-2 was the most important predictor of poor survival in this patient cohort. In patients with oropharyngeal SCC treated with external-beam radiation therapy, overexpression of COX-2 may affect clinical outcome, and COX-2 may therefore prove valuable both as a prognostic factor and as a therapeutic target.

Cyclooxygenase-2 expression in borderline ovarian tumors

OBJECTIVES

The aim of the study was to investigate by immunohistochemistry the expression of cyclooxygenase-2 (COX-2) in a single institutional series of borderline ovarian tumors (BOT). Moreover, to perform a comparative analysis, COX-2 expression was also analyzed in benign and malignant ovarian tumors.

METHODS

Paraffin-embedded sections form 51 BOT, 26 benign, and 37 malignant ovarian tumors were incubated with polyclonal antiserum against COX-2. The results were calculated as the product of the percentage of the immunostained tumor cells by the relative staining score. Cases with immunostaining values of >1 were considered COX-2-positive.

RESULTS

Thirty-four (66.7%) of fifty-one BOT were considered as COX-2-positive, and this rate was not significantly different with respect to COX-2 positivity in benign (50.0%) and in malignant (51.3%) ovarian tumors (P value = 0.23). A significantly higher percentage of COX-2 positivity was found in serous (24 of 24, 100%) with respect to mucinous (9 of 26, 34.6%) BOT (P value = 0.0001). Moreover, 7 (63.6%) of 11 endocervical-type mucinous borderline ovarian tumors were COX-2-positive with respect to only 2 of 15 (13.3%) intestinal-type mucinous BOT (P value = 0.013). The same trend was observed in benign lesions, with COX-2 positivity in 9 of 11 (81.8%) of serous versus 4 of 15 (26.7%) of mucinous tumors (P value = 0.015). On the other hand, no difference was found in the percentage of COX-2 positivity in serous (14 of 29, 48.3%) versus mucinous (5 of 8, 62.5%) ovarian carcinomas (P value = 0.22).

CONCLUSIONS

COX-2 is differently expressed in BOT according to different histotype. Moreover, an increase of COX-2 positivity was observed from mucinous intestinal BOT to frankly malignant ovarian tumors suggesting that COX-2 overexpression might be involved in mucinous ovarian carcinogenesis.

Cyclo-oxygenase 2 expression in laryngeal squamous cell carcinoma and its clinical correlates

OBJECTIVE

To assess the significance of cyclo-oxygenase 2 (COX-2) in laryngeal squamous cell carcinoma (LSCC).

STUDY DESIGN

An immunohistochemical study in which 39 patients with LSCC were included.

METHODS

Immunohistochemical staining of the paraffin-embedded tumour tissues was performed using isoform-specific COX-2 polyclonal antisera (Santa Cruz, Calif., USA). COX-2 results were compared with the clinical parameters of the patients.

RESULTS

COX-2 was detected in all tumour tissues. In the normal laryngeal tissue around the tumour area, which served as control, there was no COX-2 staining. There was no relationship between the COX-2 results and the location of the primary tumour, T stage and N stage, survival, recurrence or pulmonary metastases.

CONCLUSION

The absence of a relation between COX-2 positivity and clinical parameters may suggest an involvement of COX-2 in laryngeal carcinogenesis. Since COX-2 positivity could be detected in all LSCC specimens studied, COX-2 could serve as a therapeutic target in LSCC.

A prototype for unsupervised analysis of tissue microarrays for cancer research and diagnostics

The tissue microarray (TMA) technique enables researchers to extract small cylinders of tissue from histological sections and arrange them in a matrix configuration on a recipient paraffin block such that hundreds can be analyzed simultaneously. TMA offers several advantages over traditional specimen preparation by maximizing limited tissue resources and providing a highly efficient means for visualizing molecular targets. By enabling researchers to reliably determine the protein expression profile for specific types of cancer, it may be possible to elucidate the mechanism by which healthy tissues are transformed into malignancies. Currently, the primary methods used to evaluate arrays involve the interactive review of TMA samples while they are viewed under a microscope, subjectively evaluated, and scored by a technician. This process is extremely slow, tedious, and prone to error. In order to facilitate large-scale, multi-institutional studies, a more automated and reliable means for analyzing TMAs is needed. We report here a web-based prototype which features automated imaging, registration, and distributed archiving of TMAs in multiuser network environments. The system utilizes a principal color decomposition approach to identify and characterize the predominant staining signatures of specimens in color space. This strategy was shown to be reliable for detecting and quantifying the immunohistochemical expression levels for TMAs.

Expression of cyclooxygenase-2 in canine epithelial nasal tumors

Cyclooxygenase-2 (COX-2) is an enzyme upregulated in some human and animal tumors. Enzymatic products are associated with tumorigenic activities. Given the poor response of canine nasal tumors to radiation, we considered the possibility that some of this resistance may be associated with COX-2 expression. To test this, 21 formalin-fixed, paraffin-embedded, and archived biopsy samples from canine epithelial nasal tumors were analyzed for COX-2 expression using immunohistochemistry. The biopsies were collected from dogs prior to radiation therapy. COX-2 expression was present in 17 of 21 (81%) tumors. The expression was observed in several different tumor types, including nasal carcinomas, adenocarcinomas, and squamous cell carcinomas. Samples from five control dogs without nasal neoplasia were also analyzed for COX-2 staining. These specimens were characterized by varying degrees of lymphoplasmacytic rhinitis with scattered regions of COX-2 positive respiratory epithelial and stromal cells. Whether the intensity and distribution of COX-2 expression in nasal tumors can be used as a prognostic marker requires further investigation. A combination therapy of irradiation and a selective COX-2 inhibitor appears worthy of clinical investigation in the treatment of canine epithelial nasal tumors.

Prognostic Role of the Ratio between Cyclooxygenase-2 in Tumor and Stroma Compartments in Cervical Cancer

PURPOSE

The aim of this study was to analyze the clinical role of cyclooxygenase (COX)-2 in a large series of 175 cervical cancer patients.

EXPERIMENTAL DESIGN

Immunohistochemistry was performed on paraffin-embedded sections by using rabbit antiserum against COX-2. The tumor:stroma (T/S) ratio of COX-2 expression was used to define the overall COX-2 content in the tumor.

RESULTS

The T/S COX-2 ratio values ranged from 0.03 to 48.2 (mean +/- SE, 3.7 +/- 0.5). A total of 95 of 175 patients (54.3%) were scored as having a high (>1) T/S COX-2 ratio. In locally advanced cervical cancer patients who underwent neoadjuvant treatment, the percentage of cases showing a high T/S COX-2 ratio was greater in patients who did not respond to treatment (26 of 29 patients, 89.7%) than in patients with a partial (32 of 50 patients, 64.0%) or complete (19 of 44 patients, 43.2%) response (P = 0.0003). When logistic regression was applied, International Federation of Gynecologists and Obstetricians (FIGO) stage (chi(2) = 11.3; P = 0.0008) and T/S COX-2 ratio (chi(2) = 5.3; P = 0.021) retained an independent role in predicting a poor chance of response. Cases with a high T/S COX-2 ratio had a shorter overall survival (OS) [2-year OS, 61%(95% confidence interval 750-83)] than cases with a low T/S COX-2 ratio (2-year OS, 90%; 95% confidence interval, 81-99; P = 0.0001). In multivariate analysis, the status of T/S COX-2 IDV ratio, together with advanced stage, retained an independent negative prognostic role for OS.

CONCLUSIONS

The assessment of COX-2 status in both tumor and stroma compartment could provide valuable information to identify cervical cancer patients endowed with a very poor chance of response to neoadjuvant treatment and unfavorable prognosis.

Immunohistochemical study on overexpression of cyclooxygenase-2 in squamous cell carcinoma of the oral cavity: its importance as a prognostic predictor

Cyclooxygenase-2 (COX-2) is known as one of the critical prognostic factors in carcinomas of the various organs. However, the importance of COX-2 overexpression in oral squamous cell carcinomas has not been fully described yet. We investigated overexpression of COX-2 by immunohistochemistry in 72 surgical specimens from patients with squamous cell carcinoma of the oral cavity, and evaluated correlations between COX-2 overexpression and clinicopathologic variables. The immunoreactivity of COX-2 was cytoplasmic. COX-2 overexpression was observed in 10 (13.9%) of 72 tumours and it was well correlated with lymph node involvement at the time of surgical treatment (P=0.011) and postoperative recurrence (P=0.025), but not with the other clinicopathologic variables including age, gender, tumour stage and histological grade. In addition, COX-2 overexpression showed a close association with postoperatively disease-free survival (P=0.039) and overall survival as well (P=0.043), and multivariate analyses revealed that COX-2 overexpression was an independent predictor for disease-free survival but not for overall survival. The current study suggests that overexpression of COX-2 could impact on disease-free survival for patients with oral squamous cell carcinoma and that selective inhibition of COX-2 is a possible target for the therapeutic strategies.

Expression of cyclooxygenase-2 (COX-2) in non-neoplastic and neoplastic vulvar epithelial lesions

OBJECTIVE

Cyclooxygenase-2 (COX-2) overexpression has been associated with parameters of tumor aggressiveness and unfavourable clinical outcome in several solid tumors. We investigated by immunohistochemistry the expression of COX-2 in normal vulvar tissue, non-neoplastic vulvar epithelial lesions, vulvar intraepithelial neoplasia (VIN) and invasive vulvar cancer (IVC).

METHODS

The expression pattern of COX-2 was studied in normal vulvar tissue, in six cases of lichen sclerosus (LS), seven cases of squamous cell hyperplasia (SCH), 20 VIN, 2 Paget's disease and 36 IVC. The relationship between COX-2 expression and clinicopathologic parameters in IVC patients has been also addressed. Sections were incubated with normal rabbit serum for 15 min, then with rabbit polyclonal antiserum against human COX-2 (Cayman, Ann Arbor, MI, USA). The results were reported as mean +/- standard error (SE) of COX-2 integrated density values (IDV).

RESULTS

Higher levels of tumor/stroma COX-2 IDV ratio were found in stages III-IV (mean +/- SE = 3.5 +/- 0.8) than stages I-II disease (mean +/- SE = 1.4 +/- 0.3) (P value = 0.04). In the subgroup of stage I cases, tumor/stroma COX-2 IDV values were higher in cases with > 1 mm stromal invasion (T1b) than cases with <== 1 mm stromal invasion (T1a) (mean +/- SE = 1.6 +/- 0.3 vs. mean +/- SE = 0.6 +/- 0.1) (P = 0.033). Moreover, we observed higher tumor/stroma COX-2 IDV in cases with metastatic lymph node involvement than cases without lymph node involvement (mean +/- SE = 3.5 +/- 0.8 vs. mean +/- SE = 1.3+/-0.4) (P = 0.037).

CONCLUSION

This study suggests that COX-2 overexpression may contribute to vulvar tumorigenesis and progression. Moreover, the correlation of tumor/stroma COX-2 IDV ratio with tumor extension and metastatic lymph node involvement, which represent the major prognostic parameters in this neoplasia, implies that tumor/stroma COX-2 IDV ratio could have a prognostic role in vulvar cancer.

Differential expression pattern of cyclooxygenase-1 and -2 in head and neck squamous cell carcinoma

OBJECTIVE

The enzyme cyclooxygenase catalyzes the first step of the synthesis of prostanoids Cyclooxygenase has been shown to exist in two distinct isoforms: cyclooxygenase-1 is constitutively expressed as a housekeeping enzyme in most tissues whereas the inducible cyclooxygenase-2 has been reported to be involved in inflammatory processes and in the carcinogenesis of squamous cell carcinoma. The aim of this study was to investigate the distribution patterns of cyclooxygenase-1 and -2 in peritumoral lymphocytic infiltrates and tumor cells of head and neck carcinoma.

MATERIAL AND METHODS

Immunohistochemical analysis was performed using paraffin-embedded tumor specimens from 24 patients suffering from oropharyngeal, hypopharyngeal and oral squamous cell carcinomas.

RESULTS

We observed that cyclooxygenase-2 immunoreactivity, compared to that of cyclooxygenase-1, was significantly increased in peritumoral lymphocytic infiltrates as well as in tumor cells.

CONCLUSION

The expression of cyclooxygenase-2 in both tumor specimens and the surrounding peritumoral lymphocytic infiltrates supports the hypothesis that cyclooxygenase may be one of several important links between chronic inflammation and carcinogenesis.

Clinicopathologic significance of cyclooxygenase-2 overexpression in esophageal squamous cell carcinoma

BACKGROUND

Esophageal cancer is one of the most aggressive malignancies in the world, and whether multiple therapeutic modalities could improve long-term survival remains controversial. Recent studies have shown an increase of cyclooxygenase-2 (COX-2) expression in various malignancies, but its clinicopathologic role in esophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

From 1993 to 1997, tissue samples from 96 patients with ESCC who underwent esophagectomy at our institution were collected for analysis. Cyclooxygenase-2 expression was examined by immunohistochemical staining, and further confirmed by Western blot analysis on six frozen tissues. Clinicopathologic data were analyzed to verify the significance.

RESULTS

Cyclooxygenase-2 immunoreactivity was detected in 59 of 96 ESCC specimens (61%), and COX-2 overexpression (COX-2 high) was observed in 49% (47 of 96) of ESCCs. Statistical differences between COX-2 high and COX-2 low were found with respect to the status of distant metastasis (M factor) (p = 0.035) and tumor stage (p = 0.04). The survival was not significantly different between patients with and without COX-2 overexpression (p = 0.43). Using the Cox regression analysis, only the N factor (p = 0.0034) and M factor (p = 0.0325) were independent prognostic factors.

CONCLUSIONS

Our results showed that in patients with ESCC, COX-2 overexpression was significantly correlated with fewer metastases and less advanced stage, but had no impact on survival. The status of local or distant lymph node metastasis was the most important prognostic factor. The biological role and pathophysiologic regulation of COX-2 overexpression in ESCC deserve further investigation.

The Potential Contributions of Chronic Inflammation to Lung Carcinogenesis

A number of lines of evidence suggests that chronic inflammation contributes to the process of carcinogenesis. In this article, this theme is explored with particular emphasis on the involvement of inflammation in the development of lung cancer. A number of molecular pathways activated in chronic inflammation may contribute to lung carcinogenesis. The challenge is to conceptualize a cohesive picture of this complex biology that allows for effective pharmaceutical intervention. Initial therapeutic efforts involve strategies to block single pathways, such as with cyclooxygenase (COX) activity. However, the more that is learned about the consequences of COX activity, the more evident are the relationships of this enzyme to other classes of regulatory molecules such as the potent nuclear factor-kB. In light of this emerging picture, more global intervention strategies, such as with drug combinations, may be essential for success. Further basic study is essential to sort out possible molecular relationships and to permit elucidation of the most critical regulatory circuits. Given the complexity of these molecular interactions, well-designed clinical trials that specifically evaluate the precise effects of particular antiinflammatory drugs on lung carcinogenesis will also be critical to sort out the complexity and to validate successful approaches to arresting lung carcinogenesis.