Cyclo‐oxygenase‐2 expression in photon‐radiated and non‐radiated uveal melanomas

Abstract

ABSTRACT.Purpose: To determine and compare cyclo-oxygenase-2 (COX-2) expression in photon-radiated and non-radiated malignant uveal melanomas and to analyse the correlation between COX-2 expression and prognosis. Methods: Immunohistochemical staining for COX-2 was performed on 21 uveal melanomas that were endoresected after prior stereotactic radiotherapy with photons and on 22 tumours that were treated by endoresection without prior radiotherapy. COX-2 staining was further analysed in respect to cell type, maximal prominence, time interval between radiotherapy and surgery, apoptotic index (AI), proliferative index (PI) and the development of metastatic disease. Results: There was no difference in COX-2 expression between radiated and non-radiated melanomas (P > 0.15). COX-2 staining correlated with neither the tumour prominence (P > 0.40) nor the AI or the PI (both P > 0.35). Tumours with high COX-2 expression were significantly more likely to develop metastasis (P = 0.022). Conclusion: Radiotherapy with photons does not induce COX-2 expression in malignant melanomas of the uvea. But high COX-2 expression may be a marker for poor prognosis.

Radiation-Induced DNA Damage in Uveal Melanoma Is Influenced by Dose Delivery and Chromosome 3 Status

“…SRT was performed ( n = 23 of the 54 patients, 43%) with photons generated by a 6-megavolt linear accelerator. 8 , 21 – 23 Single-dose irradiation (sdSRT) was initially performed using retrobulbar anesthesia to immobilize the eye, which was later substituted by a functional eye immobilization device for active fixation by the patient. 23 Similarly, fractionated irradiation was performed using a modified mask that enabled the controlled fixation of a light point.…”

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

“…The COX-2 staining was shown only in 23/40 (57.5%), 52 2/15 (13.3%) 54 or 50/90 (55.6%). 55 Figueiredo et al 52 demonstrated a correlation of the COX-2 expression with the presence of epithelioid melanoma cells assessed according to Callender classification, which indicates higher cancer invasiveness, whereas no such relationships were found by Mougiakakos et al 55 The differences in evaluation of radiotherapy significance for changes in COX-2 levels in eye melanoma cells in papers 52,54,56 may be because of the effect of radiation on many processes, selection of cases for studies, but it is also likely that the choice of anti-COX-2 antibodies was important.…”

“…In studies of the COX‐2 expression in human eye melanomas, antibodies specific for fragments located at the C‐terminus of this protein were used . COX‐2 was detectable in almost all cases examined: 29/32 (90.6%), 42/42 (100%), and 17/18 (94.4%) . More divergent results were obtained using antibodies described as Ab2 in paper .…”

Novel Prognostic Immunohistochemical Markers in Uveal Melanoma-Literature Review

“…C-NFκB proteins (canonical nuclear factor-κB proteins (p65 and p50)), coordinate innate immunity and inflammation processes, particularly important in neoplastic transformation [32]. Other proteins associated with the presence of metastasis are COX-2 (Cyclooxygenase-2), an enzyme which catalyzes the prostanoid synthesis reaction [34], and p53, a cell-cycle regulatory protein [39]. PCNA (proliferating cell nuclear antigen, ATLD2), the DNA polymerase auxiliary protein involved in the control of DNA replication, is also associated with the presence of metastases [61].…”

“…COX-2 (Cyclooxygenase-2) [34] Enzyme, which catalyze the prostanoid synthesis reaction. 43 High expression correlates with presence of metastasis.…”