Immunohistochemical Expression Of Cyclooxygenase-2 Research Articles

Morphometric analysis and immunohistochemical expression of cyclooxygenase-2 in hepatitis C virus-induced fibrosis

ObjectiveThis work aimed to assess chronic hepatitis C virus-induced liver fibrosis using image analysis and to study the relation between cyclooxygenase-2 (COX-2) expression and the extent of fibrosis.Patients and methodsForty-two cases of hepatic fibrosis were included in this study. The Ishak sys

Expression of COX-2, CD44v6 and CD147 and Relationship with Invasion and Lymph Node Metastasis in Hypopharyngeal Squamous Cell Carcinoma

To assess the expression of COX-2,CD44v6 and CD147 in hypopharyngeal squamous cell carcinomas and the three biomarkers correlation with tumor invasion and lymph node metastasis of Chinese people. 101 cases of surgically excised primary tumor were included in this study, and 40 tissues of epithelium adjacent to carcinoma were used as controls. We characterized the immunohistochemical expression of COX-2, CD44v6, and CD147 in141 formalin-fixed, paraffin-embedded tissues, and measured the mean optical density (OD) of the positive area to identify the expression of the three bio-markers and relationship with tumor invasion and lymph node metastasis. Our study demonstrates that the expression of the COX-2 and CD147 were significantly increased in carcinoma tissues compared to the epithelium adjacent to carcinoma. We also observed that the expression of COX-2, CD44v6, and CD147 were significantly associated with T classification, lymph node metastasis and clinical stage. There was strong significant correlation among the three biomarkers as well. Additionally, we indicated that recurrence and ≥P50 level of COX-2 expression had an independent prognostic effect on prognosis. In conclusion, the three biomarkers play important roles in tumor invasion and lymph node metastases and might be valuable indicators of tumor metastasis in hypopharyngeal squamous cell carcinoma.

Cyclo-Oxygenase–2 Expression Is Associated With Vascular Endothelial Growth Factor C Expression and Lymph Node Metastasis in Oral Squamous Cell Carcinoma

Cervical lymph node metastasis in oral squamous cell carcinoma (OSCC) is recognized as a poor prognostic factor, although its mechanism remains unclear. Recently, cyclo-oxygenase-2 (COX-2) level has been found to correlate highly with vascular endothelial growth factor C (VEGF-C) and lymph node metastasis, as in other solid tumors. However, there has been no report of this correlation in OSCC. Therefore, the aim of this study was to investigate whether COX-2 immunohistochemical expression in OSCC was associated with VEGF-C expression, histopathologic parameters, and lymph node metastasis. Lymphatic vessel density, VEGF-C, and COX-2 immunohistochemical expression were examined pathologically in 60 specimens of invasive OSCC. Relations of histopathologic parameters to lymph node metastasis were analyzed. Expression levels of VEGF-C and COX-2 and lymphatic vessel density in the lymph node metastatic group were significantly higher than in the nonmetastatic group (P < .01). A significant correlation was found between the expression levels of VEGF-C and COX-2 (r = 0.512; P < .001). COX-2 expression was significantly related to lymph node metastasis (P = .004) and VEGF-C expression (P = .005). Univariate analysis showed that survival time was impaired by higher COX-2 and VEGF-C expression levels. Multivariate survival analysis showed that COX-2 expression was an independent prognostic factor. This study showed that VEGF-C expression was upregulated by COX-2 in OSCC. High VEGF-C expression appears to promote peritumoral lymphangiogenesis. These data indicated that lymph node metastasis is promoted by COX-2 and VEGF-C in OSCC.

Significance of Cyclooxygenase 2, EZH-2 Polycomb Group and p53 Expression in Actinic Keratosis and Squamous Cell Carcinomas of the Skin

The development and progression of squamous cell carcinoma (SCC) of the skin is characterized by an accumulation of molecular changes. The aim of this study was to investigate the association of the immunohistochemical expression of cyclooxygenase-2 (COX-2), enhancer of zeste homolog 2 (EZH-2), and p53 in actinic keratosis (AK) and SCC and detect any differences between invasive and preinvasive squamous epidermal lesions. Forty-three cases with AK, 38 with SCC, and 9 with SCC arising on AK (SCC/AK) were studied. For COX-2 immunostaining, weak or no reaction was associated with AK (58.10% of cases), whereas moderate or strong reaction with SCCs (34.2% and 39.5%, respectively). Furthermore, 88.9% of the "mixed" SCC/AK specimens demonstrated moderate reaction (χ2 = 29.924, P < 0.0001). For EZH-2 immunostaining, a weak or no reaction was observed in 62.8% of AK cases, whereas a moderate reaction was observed in 42.1% of SCCs and 77.8% of "mixed" SCC/AK cases (χ2 = 18.91, P = 0.001). Weak immunoreactivity of p53 was associated with AK (58.1%), moderate with SCC (44.7%), and strong with SCC/AK lesions (66.7%) (χ2 = 15.999, P = 0.003). COX-2, p53, but mainly EZH-2 immune expression seems to be strongly associated with the biological potential of squamous epidermal cells and seems to be differentiating SCC by comparison to AK of the skin. The value of the combined expression of these markers is worth being further investigated as an additional tool for diagnostic, prognostic, and possibly, therapeutic use.

Prognostic Significance of COX-2 Immunohistochemical Expression in Colorectal Cancer: A Meta-Analysis of the Literature

BackgroundCyclooxygenase-2 (COX-2) is believed to be an important enzyme in the pathogenesis of colorectal cancer (CRC). Correlations between the expression of COX-2 with tumor growth and distant metastasis have become an issue; thus, attention has been paid to COX-2 as a prognostic factor. Various studies examined the relationship between COX-2 immunohistochemistry (IHC) overexpression with the clinical outcome in patients with colorectal cancer, but yielded conflicting results. The prognostic significance of COX-2 overexpression in colorectal cancer remains controversial.MethodsElectronic databases updated to October 2012 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between COX-2 overexpression and survival of patients with colorectal cancer. Survival data were aggregated and quantitatively analyzed.ResultsWe performed a meta-analysis of 23 studies (n = 4567 patients) that evaluated the correlation between COX-2 overexpression detected by IHC and survival in patients with colorectal cancer. Combined hazard ratios suggested that COX-2 overexpression had an unfavorable impact on overall survival (OS) (HR [hazard ratio] = 1.193, 95% CI [confidence interval]: 1.02 ∼ 1.37), but not disease free survival (DFS) (HR = 1.25, 95% CI: 0.99 ∼ 1.50) in patients with colorectal cancer.ConclusionsCox-2 overexpression in colorectal cancer detected by IHC appears to have slightly worse overall survival. However, the prognostic value of COX-2 on survival in colorectal cancer still needs further large-scale prospective trials to be clarified.

Immunohistochemical expression of COX2 and iNOS in bladder cancer and its association with urinary schistosomiasis among Sudanese patients

AimsThe purpose of this study was to determine if any relationship exists between expression of COX2 and iNOS markers and urinary schistosomiasis in bladder cancers.MethodologyImmunohistochemical expression of COX2 and iNOS was assessed in formalin fixed paraffin wax processed tissues obtained from 155 patients with bladder cancers (87 SCC and 68 TCC) and 39 patients with benign bladder cystitis.ResultsThe overall immune-expressions of COX2 and iNOS were 71.6% and 57.2% respectively, of the 194 bladder lesions. A significant Positive association between COX2 or iNOS expression with bladder lesions (SCC, TCC and cystitis) was found (p.value = 0.000). COX2 and iNOS were co-expressed among 73(83.9%) of SCC, 15(22.1%) of TCC and 11(28.2%) of the cystitis group. The relationship between COX2 and iNOS immunostaining and Schistosomal ova positivity was statistically determined by P values 0.0565 and 0.1223 for Cox2 and iNOS, respectively.ConclusionThere are high rates of positive expression of COX2 and iNOS among Sudanese patients with Schistosomal-related bladder lesions. There might be strong association between high rates of bladder cancers and urinary Schistosomiasis in the Sudan since, the great majority of lesions were positive for COX2.

213. Cox-2 and its association with prognostic factors and response to neoadjuvant chemotherapy in patients with breast cancer

Background: In 2011 there were estimated 49,470 new cases of breast cancer with 9,170 deaths in Brazil. Despite advances in screening and treatment of this disease, the mortality rate increased 76% over the 1970-2000 period, from 5.7 per 100,000 women in 1979 to 10.15 per 100,000 women in 2002. This study aims to evaluate the immunohistochemical expression of Cox-2 and its association with tumor size, lymph node clinical status, hormone receptors, expression of HER2/neu and the pathological and clinical response to neoadjuvant chemotherapy in women with ductal carcinoma of the breast stages II or III.

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

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. 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. 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. 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.

Lymphangiogenesis in non-Hodgkin’s lymphoma and its correlation with cyclooxygenase-2 and vascular endothelial growth factor-C

We aimed to investigate the correlations between lymphangiogenesis, cyclooxygenase (COX)-2 and vascular endothelial growth factor-C (VEGF-C) in non-Hodgkin's lymphoma (NHL) and their associations with the clinical parameters of patients. A total of 75 patients diagnosed with NHL were enrolled in this study. Of the 75 patients, 14 (18.7%) had low-grade and 61 (81.3%) had aggressive lymphoma. We examined the immunohistochemical expression of COX-2 and VEGF-C and estimated lymphangiogenesis by counting lymphatic vessels expressing lymph vessel endothelial hyaluronan receptor-1 (LYVE-1). Our results showed that lymphatic vessel density (LVD) was positive in 59.0% of the cases with aggressive morphology, while the LVD positive rate of indolent lymphoma was only 28.6% (P=0.039). Both COX-2 and VEGF-C were correlated with lymphangiogenesis (P=0.030 and 0.000, respectively). The expression levels of COX-2 and VEGF-C were significantly correlated (P=0.015). LVD, COX-2 and VEGF-C were not correlated with the gender, age, lactate dehydrogenase (LDH) levels, β2 microglobulin (β2M) levels, extranodal involvement, disease stage, B symptoms or international prognostic index of the patients. In conclusion, lymphangiogenesis was correlated with aggressive histology in NHL. COX-2 and VEGF-C are inducers of lymphangiogenesis and their expression levels were correlated in NHL.

Immunohistochemical Expression of COX-2, mPGES and EP2 Receptor in Normal and Reactive Canine Bone and in Canine Osteosarcoma

Accumulating evidence suggests that cyclooxygenase (COX)-2 is involved in the pathogenesis of human and canine osteosarcoma. The aim of this study was to investigate the expression of COX-2 in normal, reactive and neoplastic canine bone and the events downstream to COX-2 that lead to prostaglandin E(2) (PGE(2)) production. COX-2, microsomal PGE(2) synthase-1 (mPGES-1) and the PGE(2) receptor (EP2) were assessed by immunohistochemistry in 12 samples of normal bone, 14 cases of fracture callus and 27 appendicular osteosarcomas. No immunoreactivity to COX-2, mPGES-1 or EP2 receptor was observed in normal bone. Fifty percent of reactive bone samples expressed COX-2 and 57% expressed mPGES-1 and EP2 receptor, although with weak labelling intensity. Ninety-three percent of osteosarcomas expressed COX-2, while mPGES-1 was expressed by 85% and EP2 receptor by 89% of the tumours. The data confirm that COX-2 is expressed at high level in osteosarcoma and support the use of COX-2 inhibitors to improve the response to chemotherapy. The possibility of blocking the EP2 or the selective inhibition of mPGES-1, rather than COX-2 activity, might decrease the incidence of adverse effects that occur due to the inhibition of prostanoids other than PGE(2).

Immunohistochemical Expression of Cox-2, Mpges-1 and Ep2 Receptor in Healthy and Reactive Canine Bone and in Osteosarcomas

Immunohistochemical Expression of Cox-2, Mpges-1 and Ep2 Receptor in Healthy and Reactive Canine Bone and in Osteosarcomas

Low-level laser irradiation, cyclooxygenase-2 (COX-2) expression and necrosis of random skin flaps in rats

Skin flaps are still a matter of concern among surgeons, as failures can occur leading to flap necrosis. However, low-level laser irradiation has been reported as an effective tool to improve the viability of ischemic flaps, yet its mechanisms of action remain unclear. We investigated the effect of low-level laser irradiation on the viability of random skin flaps in rats and determined COX-2 expression in the flap pedicle. The study animals comprised 24 EPM-1 Wistar rats which were randomly allocated into three equal groups. A cranially based dorsal random skin flap measuring 10 × 4cm was created in all the animals. In one group, laser irradiation was simulated (sham group), and in the other two groups the animals were irradiated at 12 points with 0.29J at 20mW (energy density 10.36J/cm(2), irradiance 0.71W/cm(2)), or with 7.3J at 100mW (energy density 260.7J/cm(2), irradiance 3.57W/cm(2)). These procedures were applied to the cranial half of the flap immediately after surgery and were repeated on days 2 and 5 after surgery. The percentage necrotic area was determined on day 7 after surgery by the paper template method. The immunohistochemical expression of COX-2 in the samples was given scores from 0 to 3. The necrotic area was smaller in group irradiated at 7.3J compared to sham-treated group and to the group irradiated at 0.29J (P < 0.05); there was no difference between the sham-treated group and group irradiated at 0.29J. COX-2 expression was lower in the group irradiated at 7.3J than in the sham-treated group and the group irradiated at 0.29J (P < 0.001). Low-level laser therapy was effective in decreasing random skin flap necrosis in rats using a laser energy of 7.30J per point. Laser irradiation also decreased the expression of COX-2 in the flap pedicle.

Immunohistochemical COX-2 overexpression correlates with HER-2/neu overexpression in invasive breast carcinomas: A pilot study

Cyclooxygenase-2 (COX-2) is a prostaglandin synthase that catalyzes the synthesis of prostaglandin G2 and H2. It has been shown that COX-2 plays an important role in tumorigenesis of different tumor types and it is thought to take part in breast carcinogenesis. In the present study, we aimed to investigate the relationship of immunohistochemical COX-2 expression with clinicopathological parameters, including HER-2/neu overexpression in invasive breast carcinoma (IBC).Our study population comprised 10 normal breasts, 25 ductal carcinomas in situ (DCIS), and 51 invasive breast carcinomas. Immunohistochemical overexpressions of COX-2 and HER-2/neu were investigated in sections of formalin-fixed, paraffin-embedded blocks by 3 observers.In normal breast, DCIS and IBC, the COX-2 overexpression rate was 0%, 84%, and 58.8%, respectively. In IBC, COX-2 overexpression had a significant relationship with HER-2/neu overexpression (p=0.026) and a high histological grade (p=0.026). COX-2 expression in both DCIS (n=25) and IBC (n=51) was significantly higher than in normal breast tissue (p<0.0001). In addition, the COX-2 expression rate was significantly higher in DCIS than in IBC (p=0.042).Our results indicated that COX-2 overexpression correlates with aggressive phenotypic features, such as HER-2/neu overexpression and high histological grade in IBC. Increased expression of COX-2 in both DCIS and IBC in comparison to normal breast could indicate a role in breast carcinogenesis. COX-2 overexpression may provide a clinically useful biomarker for estimating tumor aggressiveness.

Immunohistochemical expression of cyclooxygenage‐2 in melanocytic skin lesions

Several reports have shown expression of cyclooxygenase-2 (COX-2) in malignant skin tumors. COX-2 has also recently been reported as a marker of malignant melanoma (MM). Our aim was to investigate whether there is a difference in the immunohistochemical expression of COX-2 between malignant and benign melanocytic lesions of the skin. We selected 40 archival cases of MM including 10 cases of superficial spreading melanoma, 10 of lentigo maligna melanoma, 10 of nodular melanoma, and 10 of acral lentiginous melanoma. For comparison, we also selected 35 benign melanocytic lesions, which included 15 nonatypical nevi and 10 atypical nevi. The remaining 10 cases were Spitz nevi. COX-2 immunohistochemical staining was performed, and intensities were assessed quantitatively. The MM group and the benign melanocytic nevi group showed a highly statistically significant difference in the intensity of COX-2 expression (P < 0.0001). Staining intensity in the dermal component of MM cases also showed a tendency to increase with increasing tumor depth. By contrast, the intensity of the dermal component in the melanocytic nevi group decreased with increasing depth as the nevus cells matured from type A to type C cells. No statistical difference was noted between the MM and Spitz nevi cases (P = 0.20). Malignant melanoma shows stronger immunohistochemical expression of COX-2 than benign melanocytic nevi. Although COX-2 cannot be used alone to differentiate MM from melanocytic nevi, it may serve as an aid in the differential diagnosis of melanocytic skin lesions.

Cox-2 e sua associação com fatores prognósticos e resposta à quimioterapia primária em pacientes com câncer de mama

To evaluate the immunohistochemical expression of cox-2 before primary chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide (FEC) and its association with initial tumor size, lymph node status, hormone receptors, expression of HER2 and the clinical and pathological response in patients with breast cancer. We conducted a retrospective study with 41 women with histopathological diagnosis of ductal breast carcinoma. They underwent primary chemotherapy with FEC regimen (5-fluorouracil, epirubicin and cyclophosphamide) at 500mg/m2, 75mg/m2 and 500 mg/m2, respectively. Inclusion criteria were age range between 30 and 70 years, stage II to IIIA, absence of metastasis, primary tumor of the breast, single, unilateral, with ductal invasion at histology and absence of heart disease and pregnancy. To evaluate the expression of HER2/neu protein we used rabbit monoclonal antibodies. To visualize the expression of cox-2 protein we used polyclonal antibodies obtained from goats' serum. The evaluation of clinical response to treatment was performed during physical examination by measuring the major tumor axis with a pachymeter. Measurements were taken at admission and after primary chemotherapy cycles. After three chemotherapy sessions at intervals of 21 days the surgical procedure was carried out. We adopted the criteria of RECIST. After the operation we evaluated the local pathological response, which was considered complete when there was absence of invasive neoplasia and of the in situ component. In immunohistochemical assessing of estrogen receptors we used estrogen receptor NCL-ER6F11 and, for progesterone, progesterone receptor NCL-PGR-312, considering positive the staining of 10% or more tumor cells. The distribution according to UICC clinical stage classified six patients in stage IIA (14.6%), 22 in stage IIB (53.6%) and 13 stage IIIA (31.8%). The initial clinical evaluation of the major tumor axis ranged from 2.5 to 15 cm and a median of 5 cm. We identified 14 patients (34.1%) with negative lymph node status, and 27 positive (65.9%). It was observed that 19 (46.3%) were in premenopause and 22 (53.6%) in menopause. There was an association of the expression of Cox-2 to the factors associated with poor prognosis in breast cancer, such as positive lymph node status, negative hormone receptors and HER2 expression.

May cyclooxygenase-2 (COX-2), p21 and p27 expression affect prognosis and therapeutic strategy of patients with malignant pleural mesothelioma?☆☆☆

The expression of cyclooxygenase-2 (COX-2) and cell-cycle proteins (p21 and p27) proves useful in predicting prognosis and orientating therapy in many malignant tumours. Malignant pleural mesothelioma is an uncommon and lethal cancer for which there are limited treatment options. In this study, we evaluated the impact on prognosis and the influence on therapeutic strategy of immunohistochemical expression of COX-2, p21 and p27 in specimens from patients treated for malignant pleural mesothelioma. We retrospectively reviewed immunohistochemical expression of COX-2, p21 and p27 dichotomised into high and low expression from specimens of 77 consecutive patients undergoing biopsy-plus-pleurodesis (n=6), pleurectomy-decortication (n=44) or extrapleural pneumonectomy (n=27) operations for malignant pleural mesothelioma between 1987 and 2007. Histology was of epithelioid (n=50), biphasic (n=17) and sarcomatoid (n=10) subtypes. Tumour node metastasis (TNM)-stage was I (n=21), II (n=36) and III (n=20). Therapies used were sole adjuvant radiotherapy (n=17), adjuvant radio-chemotherapy (n=56) and neo-adjuvant chemotherapy plus adjuvant radiotherapy (n=4). From 2005 on, preoperative maximal standard uptake value (SUV(MAX)) was also measured by fluorodeoxyglucose positron-emission-tomography. Significance was investigated by Kaplan-Meier survival and Cox regression analysis. The median survival was 10 months. Survival was negatively influenced by histology (epithelioid vs biphasic vs sarcomatoid) (p=0.009), positive macroscopic resection margins (p=0.016), metastatic mediastinal lymph nodes (p=0.016), high COX-2 (p=0.0001) expression, low p21 (p=0.0001) expression and low p27 (p=0.001) expression. Conversely, neither the type of surgery (biopsy-plus-pleurodesis vs pleurectomy-decortication vs extrapleural pneumonectomy), nor preoperative SUV(MAX) (> or = 6.0 vs <6.0), or combined therapies (sole radiotherapy vs adjuvant radio-chemotherapy vs neo-adjuvant chemotherapy plus adjuvant radiotherapy) reached a significant level of difference. Cox regression analysis showed that only immunohistochemical triple combination of high COX-2 and low p21 and p27 expression influenced survival (p=0.0001, hazard ratio 4.7, 95% confidence intervals 3-11) regardless of type of treatment. At Cox regression analysis, a combination of high COX-2 and low p21 and p27 expression resulted in the only negative prognosticator of malignant pleural mesothelioma. With this combination, less aggressive surgical options might be preferred.

Immunohistochemical expression of cycloxygenase-2 in astrocytoma: correlation with angiogenesis, tumor progression and survival

Cyclooxygenase-2 (Cox-2) appears to play a role in the regulation of progression, invasiveness and angiogenesis of various neoplasms. Experimental studies have indicated that COX-2 regulate angiogenesis by modulating vascular endothelial growth factor (VEGF) production. The aim of this study was to evaluate the immunohistochemical expression of COX-2 in astrocytoma, in relation to VEGF expression, microvessel density (MVD), clinicopathologic factors and patient survival. 26 paraffin blocks of astrocytoma, with representative tissues and sufficient follow-up data, were evaluated immunohistochemically for protein marker expression. COX-2 expression was detected in 21 (80.7%) of 26 astrocytomas with an increased expression in grade IV (100%) as compared to grades II (63.6%) and III (83.3%) (p < 0.001), (r=0.64). A positive correlation was observed between the immunoreactive scores of COX-2, VEGF (p < 0.001), (r=0.61) and MVD (p < 0.001), (r=0.72). Also COX-2 expression was significantly associated with poor survival (p < 0.001), (r=0.58), but did not show significant difference among patient age, sex and tumor location. COX-2 is up-regulated in the majority of high-grade astrocytomas and may contribute to astrocytic tumorigenesis by promoting new vessel formation. Moreover, increased COX-2 expression is a significant negative predictor of survival. COX-2 inhibitors may represent an important therapeutic target.

Cyclooxygenase-2 expression, Ki-67 labeling index, and perifocal neovascularization in endometriotic lesions

There is a suggested pathogenetic role of cyclooxygenase-2 (COX-2) in endometriosis via angiogenesis and proproliferative mechanisms. The aim of the study was to investigate the immunohistochemical COX-2 expression in different anatomical sites of endometriosis and its correlation to proliferative activity and periendometriotic vascularization. Sixty endometrioses from different sites (ovarian, uterine, and peritoneal) were evaluated immunohistochemically for COX-2 expression. Cyclooxygenase-2 staining of 75% or more of the cells was defined as COX-2 overexpression and used as cutoff. Proliferative activity was determined by performing Ki-67-labeling index. Periendometriotic vascularization was evaluated by determining microvessel density surrounding the endometriotic focus using CD-34-immunostaining. Cyclooxygenase-2 overexpression was significant more frequent in ovarian endometriosis, when compared with uterine and peritoneal localization (70.8% versus 41.7%; P = .027). There was no significant correlation between COX-2 overexpression and perifocal neovascularization (P = .49). Endometriotic lesions with COX-2 overexpression represented reduced proliferative activity (P = .055). Cyclooxygenase-2 is expressed in the majority of endometriosis, but differences exist within the frequency of overexpression at different anatomical sites of the endometriosis. Cyclooxygenase-2 inhibitors are of clinical interest as treatment options.

Immunohistochemical Expression of Cyclooxygenase-2 (Cox-2) in Four Cases of Equine Mammary Gland Tumours

Immunohistochemical Expression of Cyclooxygenase-2 (Cox-2) in Four Cases of Equine Mammary Gland Tumours

The sunburn response in human skin is characterized by sequential eicosanoid profiles that may mediate its early and late phases.

Sunburn is a commonly occurring acute inflammatory process, with dermal vasodilatation and leukocyte infiltration as central features. Ultraviolet (UV) B-induced hydrolysis of membrane phospholipids releases polyunsaturated fatty acids, and their subsequent metabolism by cyclooxygenases (COXs) and lipoxygenases (LOXs) may produce potent eicosanoid mediators modulating different stages of the inflammation. Our objective was to identify candidate eicosanoids formed during the sunburn reaction in relation to its clinical and histological course. We exposed skin of healthy humans (n=32) to UVB and, for 72 h, examined expression of proinflammatory and anti-inflammatory eicosanoids using LC/ESI-MS/MS, and examined immunohistochemical expression of COX-2, 12-LOX, 15-LOX, and leukocyte markers, while quantifying clinical erythema. We show that vasodilatory prostaglandins (PGs) PGE2, PGF2α, and PGE3 accompany the erythema in the first 24–48 h, associated with increased COX-2 expression at 24 h. Novel, potent leukocyte chemoattractants 11-, 12-, and 8-monohydroxy-eicosatetraenoic acid (HETE) are elevated from 4 to 72 h, in association with peak dermal neutrophil influx at 24 h, and increased dermal CD3+ lymphocytes and 12- and 15-LOX expression from 24 to 72 h. Anti-inflammatory metabolite 15-HETE shows later expression, peaking at 72 h. Sunburn is characterized by overlapping sequential profiles of increases in COX products followed by LOX products that may regulate subsequent events and ultimately its resolution.—Rhodes, L. E., Gledhill, K., Masoodi, M., Haylett, A. K., Brownrigg, M., Thody, A. J., Tobin, D. J., Nicolaou, A. The sunburn response in human skin is characterized by sequential eicosanoid profiles that may mediate its early and late phases.