MicroRNA-329 upregulation impairs the HMGB2/ß-catenin pathway and regulates cell biological behaviors in melanoma.

Melanoma is responsible for the majority of deaths caused by skin cancer. Antitumor activity of microRNA-329 (miR-329) has been seen in several human cancers. In this study, we identify whether miR-329 serves as a candidate regulator in melanoma. Melanoma-related differentially expressed genes were screened with its potential molecular mechanism predicted. Melanoma tissues and pigmented nevus tissues were collected, where the levels of miR-329 and high-mobility group box 2 (HMGB2) were determined. To characterize the regulatory role of miR-329 on HMGB2 and the ß-catenin pathway in melanoma cell activities, miR-329 mimics, miR-329 inhibitors, and siRNA-HMGB2 were transfected into melanoma cells. Cell viability, migration, invasion, cell cycle, and apoptosis were assessed. miR-329 was predicted to influence melanoma by targeting HMGB2 via the ß-catenin pathway. High level of HMGB2 and low miR-329 expression were observed in melanoma tissues. HMGB2 was targeted and negatively regulated by miR-329. In melanoma cells transfected with miR-329 mimics or siRNA-HMGB2, cell proliferation, migration, and invasion were impeded, yet cell cycle arrest and apoptosis were promoted, corresponding to decreased levels of ß-catenin, cyclin D1, and vimentin and increased levels of GSK3ß and E-cadherin. Collectively, our results show that miR-329 can suppress the melanoma progression by downregulating HMGB2 via the ß-catenin pathway.

Association of anti-acidic ribosomal protein P0 and anti-galectin 3 antibodies with the development of skin lesions in systemic lupus erythematosus.

OBJECTIVE: The specific autoantibodies and antigens that mediate systemic lupus erythematosus (SLE)-related organ injuries remain largely unknown. This study was undertaken to investigate the antibody-mediated immune response that leads to SLE skin lesions. METHODS: The study included 85 SLE patients with lupus-specific skin lesions and 31 without skin lesions. The reactivity of serum antibody with skin antigens was determined by immunoblotting using human foreskin as the substrate. Skin antigens were identified using mass spectrometry. Serum antibody was isolated by affinity purification and was injected intracutaneously into mouse skin to determine pathogenicity. Serum antibody levels were monitored by enzyme-linked immunosorbent assay. RESULTS: We determined that 78% of the patients with skin lesions had serum antibodies reactive with 35-kd and/or 25-kd skin antigens, which was significantly higher than the percentage of patients without skin lesions (P < 0.0001), suggesting a correlation between immune response and skin lesions. Acidic ribosomal protein P0 (RPLP0) and galectin 3 were 2 target antigens identified from 35-kd and 25-kd proteins, respectively. Purified serum anti-RPLP0 and anti-galectin 3 antibodies induced lupus-like histologic changes after intracutaneous injection. Anti-RPLP0 and anti-galectin 3 antibody levels were significantly higher in SLE patients than in healthy controls and decreased with skin recovery. Anti-galectin 3 antibody levels were not significantly higher in SLE patients than in patients with dermatomyositis or scleroderma, but strongly related to lupus cutaneous vasculitis. Additionally, levels of the 2 antibodies were positively correlated with leukopenia and C3 deficiency, and the anti-RPLP0 antibody level was also positively correlated with arthritis and SLE disease activity. CONCLUSION: Our findings indicate that the immune response mediated by serum anti-RPLP0 and anti-galectin 3 antibodies plays a key role in the pathogenesis of SLE skin lesions. These findings provide new insights into the mechanism of SLE-related organ disorders.