Comparison of the mechanisms of intralesional steroid, interferon or verapamil injection in the treatment of proliferative scars

Abstract

To investigate the effects of intralesional steroid, interferon alpha-2b or verapamil injection on proliferation, apoptosis and TGF-beta1 expression in keloid and hypertrophic scar in vivo. 6 patients with keloids and 6 patients with hypertrophic scar were treated with intralesional injection of triamcinolone acetonide (40 mg/ml) or IFN alpha-2b (15 x 10(5) U/ml) or verapamil (2.5 mg/ml). Samples were collected on the 7th day after intralesional injection. Samples of untreated keloid and hypertrophic scar and normal skin were used as control. Expression of PCNA and TGF-beta1 was detected in situ by immunohistochemical staining, and apoptosis was detected in situ by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL). 1) Triamcinolone acetonide could prohibit proliferative scars through inhibiting cell proliferation and TGF-beta1 expression, as well as inducing apoptosis. 2) IFN alpha-2b could prohibit proliferative scars through inhibiting cell proliferation and TGF-beta1 expression, but not inducing apoptosis; 3) Verapamil could also prohibit proliferative scars through inhibiting proliferation and TGF-beta1 expression in fibroblasts, as well as inducing apoptosis. While the effect of inducing apoptosis was stronger than that of triamcinolone acetonide, the effect of inhibiting TGF-beta1 expression was weaker than those of triamcinolone acetonide and IFN alpha-2b. Although intraleional injection of steroid, interferon alpha-2b or verapamil were all effective in the treatment of keloid and hypertrophic scar, their mechanisms are not similar.