Immunohistochemical detectability of cyclooxygenase‐2 expression in cells of human melanocytic skin lesions: A methodological review

Abstract

Increased cyclooxygenase‐2 (COX‐2) expression is thought to support tumorigenesis through various mechanisms and is analyzed as a potential cancer marker. In 18 studies, COX‐2 expression in melanocytic lesions of human skin was examined immunohistochemically. However, results obtained by individual research groups differ in terms of detection frequency and level of this protein, as well as localization of stained cells within tumor. Possible reasons for the discrepancies are analyzed in this review: the application of different antibodies, the use of standard histopathological sections or tissue microarrays and the analyzes of staining results based on different algorithms. COX‐2 level is significantly lower in nevi than in melanomas, increases gradually with progression of these malignant cancers and reaches the highest values in metastases. These gradual changes in COX‐2 expression appear to be difficult to analyze based only on subjective assessment of staining intensity. The most convergent data were obtained using antibodies for N‐terminal fragments of COX‐2 protein and analyzing results based on calculation of percentage fraction of positive cells. The extent of stained area in specimen thus appears to be more important than the intensity of staining in terms of evaluation of COX‐2 performance as a diagnostic and prognostic marker of cutaneous melanoma.

The detectability of intraepidermal melanocytes—A narrative review of immunohistochemical studies

“…It is known that the tissue processing as well as the selection of an appropriate type of antibody may influence the obtained results. [69][70][71] Unfortunately, the details of applied methods usually are not described in case reports that makes the analysis of this problem difficult. Another reason for the discrepancies of the results may be the heterogeneity of the group of diseases described as lichenoid dermatoses.…”

“…One possible reason for these differences in the immunohistochemical detectability rate of Melan‐A/Mart‐1 in “pseudomelanocytic nests” may be the use of different reagents and material treatment. It is known that the tissue processing as well as the selection of an appropriate type of antibody may influence the obtained results 69–71 . Unfortunately, the details of applied methods usually are not described in case reports that makes the analysis of this problem difficult.…”

Оценка Экспрессии Тучных Клеток И СОХ2 В Пределах Фиброэпителиальных Полипов Кожи У Пациентов С Ме-Таболическим Синдромом И Сахарным Диабетом 2 Типа

“…Показано, що підвищення COX2-опосередкованої продукції PGE асоційоване з розвитком 12-O-тетрадеканоїл-форбол-13-ацетат індукованих папілом у мишей [15]. Вважається, що COX2-залежний синтез ПГE2 відіграє ключову роль у патогенезі тривалої гіперплазії епідермісу та туморогенезі, тоді як використання селективних інгібіторів COX2 обмежує розвиток гіперплазії та запобігає прогресії немеланоцитарних пухлин шкіри [16].…”