Expression of telomerase reverse transcriptase in radiation-induced chronic human skin ulcer

The objective ofthis study was to investigate the expression of the catalytic subunit of telomerase, telomerase reverse transcriptase (TRT), and the possible relationship between the TRT expression and poor healing or cancer transformation in radiation-induced chronic human skin ulcer. Rabbit antibody to human TRT and SP immunohistochemical method were used to detect TRT expression in 24 cases of formalin-fixed, paraffin-embedded chronic human skin ulcer tissues induced by radiation, 5 cases of normal skin, 2 of burned skin, and 8 of cancer. The positive rate ofTRT expression in chronic radiation ulcers was 58.3% (14/24), of which it was strongly positive in 41.7% cases (10/24) and weakly positive in 16.7% (4/24). TRT expression was 0% in normal (0/5) and burned skin (0/2), and 100% in cancer cases (8/8). The strongly positive expression of TRT was observed almost always in the cytoplasm and nucleus of squamous epithelial cells of the epidermis but it was negative or only weakly positive in the smooth muscle and endothelia of small blood vessels and capillaries, and in fibroblasts. Chronic inflammatory cells, plasmacytes, and lymphocytes were weakly positive for TRT. TRT expression could be involved in the poor healing caused by sclerosis of small blood vessels and lack of granulation tissue and in the cancer transformation of chronic radiation ulcer.