First study on the immunohistochemical expression of cyclooxygenase-2 and clinicopathological association in canine hepatoid gland neoplasms

Background and Aim: Hepatoid gland neoplasms (HGNs) constitute one of the most common cutaneous tumors that arise from perianal glands in dogs and are clinically characterized by rapid growth. Cyclooxygenase-2 (COX-2), the inducible form of the enzyme, is associated with several hallmarks of tumorigenesis. Its expression has been confirmed in several human and animal neoplastic tissues, but there are no reports in hepatoid gland tissues. Therefore, this study aimed to investigate COX-2 immunoexpression in canine HGNs, compare the expression among groups of normal hepatoid glands, hepatoid gland adenomas (HGAs), hepatoid gland epitheliomas (HGEs), and hepatoid gland carcinomas (HGCs), and assess the association of the COX-2 expression with clinicopathological features. Materials and Methods: Sixty-one formalin-fixed paraffin-embedded canine hepatoid gland tissues (20 samples of HGAs, 16 of HGEs, 15 of HGCs, and 10 of normal hepatoid glands) were analyzed for COX-2 expression using immunohistochemistry with scoring for percentage positivity and intensity. Multiple comparisons of COX-2 expression among normal and neoplastic hepatoid glands and the associations between COX-2 expression and clinicopathological features were analyzed. Results: Cyclooxygenase-2 expression was not detected in 60% of normal hepatoid glands and 25% of HGAs. Seventy-five percent of HGAs had a weak expression, while 43.7% and 56.3% of HGEs showed weak and moderate expression, respectively. The expression of HGCs ranged from weak (13.3%) to moderate (33.3%) and strong (53.3%). The immunoreactivity score of COX-2 labeling was significantly different among the normal and neoplastic hepatoid glands (p < 0.0001). The highest score was observed in the HGCs. Only in HGCs, the strong COX-2 expression was significantly associated with some clinicopathological features, including tissue invasion (p = 0.007) and necrosis (p = 0.029). Conclusion: These results suggest that COX-2 may play a role in the modulation of neoplastic cell growth. These preliminary data lead to further investigation on the potential of COX-2 expression as a prognostic indicator and COX-2 inhibitors for canine HGCs treatment.

Cytotoxicity and Pro-Apoptotic, Antioxidant and Anti-Inflammatory Activities of Geopropolis Produced by the Stingless Bee Melipona fasciculata Smith

Geopropolis is produced by some stingless bee species, such as Melipona fasciculata Smith, a native species from Brazil. This study aims to investigate the antioxidant and anti-inflammatory activities and cytotoxicity effects of geopropolis hydroethanolic extracts against lung (H460 and A549) and ovarian (A2780 and ES2) cancer cell lines and non-tumor (HUVEC) cell lines using chemical identification by LC/MS/MS analysis and in silico assays to determine which compounds are associated with bioactivity. The antioxidant activity of extracts and inhibitory activity against COX enzymes were assessed by in vitro assays; cytotoxicity effect was evaluated by the MTT assay; cell cycle was assessed by flow cytometry and apoptosis by Western blotting. The geopropolis extracts showed great radical scavenging potential, preferential inhibition of COX-2, decreased cancer cell viability, non-cytotoxic effects against the non-tumoral cell line, besides modulating the cell cycle and inducing cancer cell apoptosis through the activation of caspase-3 and PARP protein cleavage. The in silico study suggests that corilagin, typhaneoside, taraxerone and marsformosanone, identified by LC/MS/MS, can be associated with anti-inflammatory activity and cytotoxic effects. Thus, the current study suggests the potential of geopropolis concerning the research field of new pharmacological alternatives regarding cancer therapy.

Cyclooxygenase-2 expression as a prognostic factor in pediatric classical Hodgkin lymphoma

PURPOSE

Cyclooxygenase-2 (COX-2) is an inflammation-related enzyme that has been shown to have a role in tumor initiation, angiogenesis, and proliferation. It has been demonstrated that COX-2 expression is increased in many tumors and is a negative prognostic parameter. Our objective is to investigate the prognostic value of COX-2 expression in pediatric patients with classical Hodgkin lymphoma (CHL).

METHODS

This was a retrospective analysis in pediatric patients (n = 127) diagnosed with CHL and treated at the pediatric oncology department, National Cancer Institute, Cairo University, January 2005-June 2013. We correlated COX-2 immunostaining in Reed-Sternberg (RS) cells with clinical variables and outcome.

RESULTS

COX-2 was expressed on 38.6% of RS cells. The median follow-up time was 48.4 months (range 4-114 months). The 5-year OS and PFS, in COX-2(+ve) versus COX-2(-ve) was 85.3% versus 96.0% (p = 0.248) and 78.6% versus 84.3% (p = 0.354), respectively. A multivariate analysis showed that COX-2(+ve) was not significantly associated with the 5-year OS (HR = 2.9; 95% CI 0.7-12.4, p = 0.149) or with the 5-year PFS (HR = 1.4; 95% CI 0.6-3.2, p = 0.490). High-risk patients in the COX-2(+ve) group had a significantly lower 5-year OS (p = 0.021). The 5-year PFS was significantly lower in the COX-2(+ve) group with B symptoms (p = 0.023) and bulky disease (p = 0.028). Radiotherapy was given only to high-risk patients; survival was much better in radiation-treated children in both the Cox-2(+ve) and Cox-2(-ve) groups. The magnitude of the radiotherapy effect was also greater in the Cox-2(+ve) group, but this difference was not statistically significant.

CONCLUSION

COX-2 expression showed a tendency to be a poor prognostic factor, but it failed to provide meaningful independent information. Further larger studies are needed to investigate COX-2 as a prognostic factor and potential therapeutic target.

Staphylococcus aureus induces COX-2-dependent proliferation and malignant transformation in oral keratinocytes

The COX-2/PGE₂ axis can play roles in mediating the progression of tumor. COX-2 induction was observed in oral cancer. In our previous study, we found Staphylococcus aureus, a pathogen prevalent in oral cancer, can activate the COX-2/PGE₂ pathway in human oral keratinocyte (HOK) cells. Here, we investigated the proliferation of HOK cells affected by COX-2 induction and the role of COX-2 induction in the malignant transformation of HOK cells. We found S. aureus was able to facilitate HOK cell proliferation through upregulating COX-2 expression. With the induction of COX-2, expression of oral cancer-associated genes cyclin D1 was upregulated and p16 was downregulated. Transcriptome analysis showed that the “NF−kappa B signaling pathway” and “TNF signaling pathway” had the highest enrichment of differentially expressed genes (DEGs) with COX-2 over-expression. Seven upregulated genes (jun, tlr4, cxcl1, lif, cxcl3, tnfrsf1β, and il1β) in these two pathways were critical for the increased proliferation of HOK cells and might be associated with COX-2. Malignant transformation of cells was evaluated by soft agar colony formation assay and S. aureus infection promoted HOK cell colony formation. These results suggest the potential of S. aureus to induce the infection-associated malignant transformation of oral epitheliums through COX-2 activation.

GW627368X inhibits proliferation and induces apoptosis in cervical cancer by interfering with EP4/EGFR interactive signaling

PGE2, the major product of cyclooxygenases implicated in carcinogenesis, is significantly upregulated in cervical cancer. PGE2 via prostanoid receptor EP4 stimulates proliferation and motility while inhibiting apoptosis and immune surveillance. It promotes angiogenesis by stimulating the production of pro-angiogenic factors. The present study demonstrates GW627368X, a highly selective competitive EP4 antagonist, which hinders cervical cancer progression by inhibiting EP4/epithelial growth factor receptor (EGFR) interactive signaling. GW627368X reduced protein kinase A (PKA) phosphorylation which in turn leads to decreased cAMP response element-binding protein (CREB) activation. Decreased PKA phosphorylation also directly enhanced Bax activity and in part reduced glycogen synthase kinase 3 (GSK3)β phosphorylation. Owing to the interactive signaling between EP4 and EGFR, GW627368X lowered EGFR phosphorylation in turn reducing Akt, mitogen-activated protein kinase (MAPK) and GSK3β activity significantly. Sublethal dose of GW627368X was found to reduce the nuclear translocation of β-catenin in a time dependent manner along with time-dependent decrease in cytoplasmic as well as whole-cell β-catenin. Decreased CREB and β-catenin transcriptional activity restricts the aberrant transcription of key genes like EP4, cyclooxygenase (COX)-2, vascular endothelial growth factor and c-myc, which ultimately control cell survival, proliferation and angiogenesis. Reduced activity of EGFR resulted in enhanced expression of 15-hydroxyprostaglandin dehydrogenase increasing PGE2 degradation thereby blocking a positive feedback loop. In xenograft model, dose-dependent decrease in cancer proliferation was observed characterized by reduction in tumor mass and volume and a marked decrease in Ki67 expression. A diminished CD31 specific staining signified decreased tumor angiogenesis. Reduced expression of pAkt, pMAPK, pEGFR and COX-2 validated in vitro results. GW627368X therefore effectively inhibits tumor survival, motility, proliferation and angiogenesis by blocking EP4/EGFR interactive signaling. EP4 is a potent therapeutic target in cervical cancer and can be explored in combination with conventional therapies to attain superior outcomes and to overcome complications associated with organ toxicities, therapeutic resistance and disease relapse.

COX-2 inhibitors: a novel strategy in the management of breast cancer

Cyclooxygenase-2 (COX-2) inhibitors are common anti-inflammatory drugs with pleiotropic, endogenous actions that could be useful in the management of breast cancer. Here, we provide a complete understanding of the biochemistry of COX-2 and discuss the various molecular mechanisms behind its increased expression in breast cancer. We also analyze the possible mechanisms responsible for the anticancer effect of COX-2 inhibitors and provide an overview of the available preclinical and clinical data on the use of COX-2 inhibitors in breast cancer. Finally, we describe a mathematical model of the relation between the structure and biological potency of promising new COX-2 inhibitors (trans-stilbenes) using a 2D quantitative structure-activity relationship (QSAR) technique.

Prognostic value of COX-2, P53, and EZH-2 evaluated by quantitative image analysis in premalignant and malignant breast lesions

BACKGROUND

Cytological differential diagnosis of atypical hyperplasia and well differentiated breast carcinoma may be challenging, because sometimes there is an overlap between the cytomorphological features of these lesions. The aim of the study was to investigate COX-2, EZH-2, p53 expression in carcinomas and the gray zone of breast cytology categories of atypical hyperplastic lesions with regard to biological behavior of the tumor.

METHODS

FNA speciments from 100 patients with breast hyperplastic lesions and cancer were investigated by immunocytochemistry and a quantitative analysis for COX-2, p53, and EZH-2.

RESULTS

Extent of staining for COX-2 correlated with percentage of positive for EZH-2 (P < 0.0001) and p53 nuclei (P < 0.001). The intensity of COX-2 was lower in the carcinoma group (118.57 ± 12.43) than in the hyperplastic (127.16 ± 11.71) group (P = 0.006). On the contrary the mean value of staining extent was greater in the adenocarcinoma cases (15.96 ± 13.03) than in hyperplastic (4.04 ± 1.94) cases (P < 0.0001). The percentage of EZH-2 and p53 positive cells correlated with the histological type of the lesions (P = 0.001 and P = 0.011, respectively). There was also a statistically significant relation between tumor size and expression of COX-2 (P = 0.007) and EZH-2 (P = 0.010).

CONCLUSION

Our study showed that the expression of COX-2, EZH-2, and p53 as determined by immunocytochemistry at quantitative level may be a predictor for distinguishing cytologically atypical hyperplastic from malignant breast lesions and may be regarded as potential prognostic factor in breast cancer patients.

Antiproliferative diarylpyrazole derivatives as dual inhibitors of the ERK pathway and COX-2

A series of 3,4-diarylpyrazole-1-carboxamide derivatives was designed and synthesized. A selected group of the target compounds was tested for in vitro antiproliferative activities over a panel of 60 cancer cell lines at the National Cancer Institute (NCI, Bethesda, MD, USA) at a single-dose concentration of 10 μm, and the four most active compounds 9a, 9l, 9n, and 10o were further tested in a five-dose testing mode to determine their IC50 values over the 60 cell lines. In addition, a selected group of target compounds were tested for inhibitory effect over cyclooxygenase isozymes. Compounds 9a, 9l, 9n, and 10o were also tested for MEK and ERK kinase inhibitory activity using Western blot assay. Compound 10o was selective toward melanoma cell line subpanel, and its antiproliferative activity may be attributed to selective cyclooxygenase-2 inhibition and ERK pathway inhibition.