[Expression of pituitary tumor-transforming gene-1 and its pathogenic role in systemic sclerosis].

OBJECTIVE: To investigate the expression of tumor-transforming gene-1 (PTTG1) in systemic sclerosis (SSc) and its role in fibrosis. METHODS: Skin biopsy samples were collected from 21 patients with SSc and 22 patients with healthy skin for detecting the mRNA and protein expressions of PTTG1 using real-time PCR (RT-PCR) and immunohistochemistry, respectively. In cultured primary human dermal fibroblasts, PTTG1 expression was knocked down via RNA interference (siRNA), and the mRNA expression levels of PTTG1 and the fibrosis-related genes α-SMA, COL1A1, COL1A2, and COL3A1 were detected using RT-PCR; the proliferation of the cells was assessed using a real-time cell proliferation detection system. RESULTS: Compared with those in normal skin samples, the mRNA and protein expressions of PTTG1 increased significantly in the skin tissue of patients with SSc (P < 0.05). In cultured primary skin fibroblasts, the expression of PTTG1 mRNA was positively correlated with those of α-SMA (R(2)=0.8192, P < 0.05), COL1A1 (R(2)=0.6398, P < 0.05), COL1A2 (R(2)=0.316, P < 0.05) and COL3A1 mRNAs (R(2)=0.3727, P < 0.05). Interference of PTTG1 expression significantly inhibited the cell proliferation, obviously lowered the expressions of fibrosis-related genes, and down-regulated the expression of collagen in the fibroblasts. CONCLUSIONS: PTTG1 is highly expressed in skin tissues of patients with SSc, and PTTG1 knockdown can reduce the activity of the dermal fibroblasts, suggesting a close correlation of PTTG1 with fibrosis in SSc.