Expression of cyclooxygenase-2 in benign naevi and during human cutaneous melanoma progression.

Department of Medical Biology, Institute of General and Molecular Biology, Nicolaus Copernicus University, Toruń, Poland.
Melanoma Research (Impact Factor: 2.1). 03/2006; 16(1):29-36. DOI: 10.1097/01.cmr.0000194430.77643.a0
Source: PubMed

ABSTRACT Cyclooxygenase-2 (COX-2) is an enzyme that plays an important role in the production of prostaglandins. Numerous studies have demonstrated increased levels of COX-2 in human cancers of different types. It is thought that COX-2 may be involved in the development and progression of malignant tumours. However, data on the changes in COX-2 expression during the development and progression of human melanoma are relatively limited. Moreover, the results reported by different groups disagree to a large extent. The aim of this work was to evaluate whether COX-2 protein might be considered a potential molecular marker of melanoma progression. The expression of COX-2 was determined immunohistochemically in formalin-fixed, paraffin-embedded specimens of 64 human melanocytic skin tumours (17 naevi, 36 primary cutaneous melanomas and 11 lymph node melanoma metastases, with six pairs of primary and metastatic lesions obtained from the same patients). It was found that the expression level of COX-2 was dependent on both the stage and histopathological type of the melanoma. Collectively, our data indicate that changes in the expression level of COX-2 are correlated with the development and progression of human melanoma, and imply that the COX-2 protein may be considered a potential prognostic and predictive marker in malignant melanoma.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Cyclooxygenase-2 (COX-2), overexpressed in many types of human cancer, may be valuable marker for human melanoma. However, there are discrepancies between expression levels detected by different groups. Majority of the studies was carried out using standard paraffin sections. Tissue microarrays (TMAs) might enable analysis of COX-2 expression in numerous lesions. Our study assesses to what extent reprocessing of tissue samples used for preparing TMAs may influence reproducibility of data obtained for standard sections. The study included TMAs and standard histopathologic sections. COX-2 was detected by immunohistochemistry with two primary antibodies targeting different epitopes. COX-2 expression levels detected with both antibodies in standard sections were similar as in our previous study. Surprisingly, results obtained in TMAs were significantly different. While one of the antibodies yielded for TMAs results similar to standard sections, COX-2 expression levels found with the second antibody were very low and expression patterns strikingly different from those observed for standard sections and for both TMAs studied with the first antibody. Good performance of the antibodies found in standard sections of human skin and melanocytic lesions does not guarantee similar results in TMAs. The finding discloses new aspect of immunohistochemical assays involving TMAs.
    Pathology - Research and Practice 09/2014; 210(9). DOI:10.1016/j.prp.2014.04.014 · 1.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In view of the increasing incidence of melanoma, it is critical to find effective preventive approaches. Contradictory evidence has been reported with regard to the possible association of aspirin use and the risk of melanoma. We review these studies and seek to elucidate the mechanism by which aspirin may produce a chemoprotective effect against melanoma.
    Journal of the American Academy of Dermatology 01/2014; 70(1):187-91. DOI:10.1016/j.jaad.2013.09.045 · 5.00 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cyclooxygenase-2 (COX-2) is a potential target for chemoprevention and cancer therapy. Celecoxib, a selective COX-2 inhibitor, inhibits cell growth of various types of human cancer including malignant melanoma. In dogs, oral malignant melanoma represents the most common oral tumor and is often a fatal disease. Therefore, there is a desperate need to develop additional therapeutic strategies. The purpose of this study was to investigate the anticancer effects of celecoxib on canine malignant melanoma cell lines that express varying levels of COX-2. Celecoxib induced a significant anti-proliferative effect in both LMeC and CMeC-1 cells. In the CMeC cells, treatment of 50 μM celecoxib caused an increase in cells in the G0/G1 and a decreased proportion of cells in G-2 phase. In the LMeC cells, 50 μM of celecoxib led to an increase in the percentage of cells in the sub-G1 phase and a significant activation of caspase-3 when compared to CMeC-1 cells. In conclusion, these results demonstrate that celecoxib exhibits antitumor effects on canine melanoma LMeC and CMeC-1 cells by induction of G1-S cell cycle arrest and apoptosis. Our data suggest that celecoxib might be effective as a chemotherapeutic agent against canine malignant melanoma.
    Research in Veterinary Science 06/2014; DOI:10.1016/j.rvsc.2014.03.003 · 1.51 Impact Factor