Increased expression of cyclooxygenase-2 in human salivary gland tumors

Interaction between escitalopram and ibuprofen or paracetamol: DFT and molecular docking on the drug-drug interactions

A large number of drugs are introduced each year to treat different diseases. Most of the time, patients suffer from more than one health problem which makes it necessary to take multiple drugs. When drugs are combined, the problem of drug-drug interaction becomes relevant. In this work, we studied the drug-drug interaction between escitalopram and ibuprofen or paracetamol using density functional theory and quantum theory of atoms in molecules. The results suggest that following the interactions, the activity of drugs changes according to site of interaction. Most reactive and most stable interactions would be preferable for the purpose of use. The in silico drug-likeness studies show that escitalopram and paracetamol couple is more bioavailable than escitalopram and ibuprofen couple. Moreover, in order to gain additional insights into the mentioned drugs' interactions, the drugs were docked separately and jointly against the potential targets for antidepressants and NSAIDs, namely 6HIS and 2PXX. The molecular docking results showed a potential improvement of the effectiveness of the drugs after combining by forming hydrogen bonds, hydrophobic contacts and π…π stacking.Communicated by Ramaswamy H. Sarma.

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.

Abnormal COX2 protein expression may be correlated with poor prognosis in oral cancer: a meta-analysis

Background. The prognostic significance of COX2 for survival of patients with oral cancer remains controversial. Thus, the meta-analysis was performed in order to identify COX2 expression impact on prognosis of oral cancer. Method. Relevant literatures were searched using the following electronic databases without any language restrictions: Web of Science, the Cochrane Library Database, PubMed, EMBASE, CINAHL, and CBM. Version 12.0 STATA software (Stata Corporation, College Station, Texas, USA) was used for the current meta-analysis. Odds ratios (ORs) and hazard ratios (HRs) with their corresponding 95% confidence interval (95% CI) were also calculated to clarify the correlation between COX2 expression and prognosis of oral cancer. Results. Final analysis of 979 oral cancer patients from 12 clinical cohort studies was performed. The meta-analysis results show that COX2 expression in cancer tissues was significantly higher than those in normal and benign tissues (all P < 0.05). Combined HR of COX2 suggests that positive COX2 expression has a shorter overall survival (OS) than those of negative COX2 expression (P < 0.05). Conclusion. The meta-analysis study shows that elevated COX2 expression may be associated with the pathogenesis of oral cancer and with a worse prognosis in oral cancer patients.

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.

Spontaneous adenocarcinoma immunoreactive to cyclooxygenase-2 and transforming growth factor-beta1 in the buccal salivary gland of a Richardson's ground squirrel (Spermophilus richardsonii)

The ground squirrel is used as an experimental animal because of its unique biological nature. A 3-year-old female Richardson's ground squirrel developed a mass, 1.5 cm in diameter, in the buccal mucosa. The mass consisted of neoplastic epithelial cells showing acinar, ductular, intraductal papillary, solid, and lobular growth patterns; the cells were immunoreactive to cytokeratin, cyclooxygenase-2 (a marker of malignancy) and TGF-beta1. After resection, the tumor recurred with increased area having a solid or lobular pattern with little differentiation. This tumor was diagnosed as an adenocarcinoma arising from the buccal gland, the first case reported in the ground squirrel. A prominent desmoplastic reaction was present. The interstitial cells reacted to alpha-smooth muscle actin and vimentin, indicating a myofibroblastic nature, presumably induced by epithelial TGF-beta1.

Overexpression of cyclooxygenase-2 correlates with cytoplasmic HuR expression in salivary mucoepidermoid carcinoma but not in pleomorphic adenoma

BACKGROUND

The overexpression of cyclooxygenase (COX)-2 in several human carcinomas suggests that COX-2 is related to carcinogenesis. Although COX-2 expression has been shown to be up-regulated in carcinomas of the salivary gland, its mechanisms are not completely understood. HuR is an mRNA-binding protein that controls the stability of certain transcripts including COX-2.

METHODS

The expression of COX-2 and HuR was determined by immunohistochemistry in 28 cases of salivary pleomorphic adenoma and 18 cases of salivary mucoepidermoid carcinoma.

RESULTS

28.6% and 72.2% of the pleomorphic adenomas and mucoepidermoid carcinomas showed high COX-2 expression respectively. 35.7% of pleomorphic adenomas and 72.2% of mucoepidermoid carcinomas were tested positive for HuR in the cytoplasm of tumor cells. There was a correlation between a high COX-2 immunoreactivity and cytoplasmic HuR expression in mucoepidermoid carcinomas but not in pleomorphic adenomas.

CONCLUSION

This study suggests that cytoplasmic HuR is correlated with COX-2 expression in salivary mucoepidermoid carcinomas. In addition, the immunoreactivity of COX-2 and cytoplasmic HuR might be used to evaluate the nature of a borderline malignancy in the salivary glands.

Hepatocyte growth factor expression correlates with cyclooxygenase-2 pathway in human salivary gland tumors

It has been reported that cyclooxygenase-2 (COX-2) plays roles in cell proliferation, tumor invasion and inhibition of apoptosis. We reported COX-2 expression in salivary adenoma and its involvement in inhibition of apoptosis. COX-2 is known to induce a number of cytokines and growth factors. On the other hand, hepatocyte growth factor (HGF) plays roles such as cell migration, proliferation, angiogenesis and inhibition of apoptosis. Recently it has been reported that HGF also plays a role in tumor differentiation in salivary gland tumors. So, we investigated that whether COX-2 expression affected HGF expression clinicopathologically, and discussed the roles of COX-2 pathway in salivary gland tumors. Tissues samples were pleomorphic adenomas (n = 40) obtained surgically. COX-2 expression and HGF expression were examined immunohistochemically. Immunostaining intensities of COX-2 and HGF were classified as +3 to 0. Spearman's rank correlation was used to examine correlation of COX-2 and HGF expression. Furthermore, a salivary gland tumor cell line, HSG, was cultured after administration of either 0, 10, 100 units of COX-2 and quantification of HGF mRNA was analyzed by Real Time PCR using the Light Cycler System. In pleomorphic adenoma, COX-2 and HGF were mainly expressed in luminal tumor cells, and the sites of expression of the two were almost the same. Immunostaining intensity of COX-2 expression was significantly correlated with intensity of HGF expression (p = 0.003, r = 0.457). Moreover, the content of HGF mRNA expression increased when COX-2 was administered to salivary gland tumor cell line HSG. It is suggested that COX-2 expression may induce HGF expression in salivary gland tumors.

Expression of cyclooxygenase-2, Bcl-2 and Ki-67 in pleomorphic adenoma with special reference to tumor proliferation and apoptosis

The present report is of immunohistochemical and cell biological studies on cyclooxygenase(COX)-2, Bcl-2 and Ki-67 in pleomorphic adenoma (n = 35). Pleomorphic adenomas from oral minor glands (n = 15), parotid gland (n = 11), Submandibular gland (n = 8) were studied and sublingual gland (n = 1). Expression of COX-2, Bcl-2 and Ki-67 was examined immunohistologically. Immunostaining intensity of COX-2 and Bcl-2 was classified into expression levels from +3 to 0. The positivity to Ki-67 was evaluated by counting the number of positive cells per 1000 cells, and the values were expressed in as percentage. Apoptotic cells were detected using the modified TUNEL method. Expression of COX-2 mRNA was analyzed by real time PCR using fresh tissues of 4 cases. The relationship between morphological findings and the level of COX-2 mRNA expression was analyzed using a laser capture microdissection (LCM). The results of immunohistochemistry and gene analysis using LCM revealed expression of COX-2 mainly in luminar tumor cells. Expression of COX-2 in pleomorphic adenoma was correlated with expression of Bcl-2 statistically (p = 0.044 < 0.05, r = 0.342). There was only a small number of apoptotic cells cells, and intensity of expression of TUNEL was not correlated with the expression of COX-2 (p = 0.463 > 0.05, r = -0.128). There was no statistical correlation between COX-2 and Ki-67 (p = 0.97 > 0.05, r = -0.07). It is suggested that COX-2 may inhibit apoptosis mediating Bcl-2 expression in pleomorphic adenoma, rather than playing a role in cell proliferation.