RESUMEN
The present study aimed to evaluate the efficacy and safety of in situ immunotherapy with dinitrophenyl (DNP) hapten in combination with laser therapy for patients with malignant melanoma (MM). Between February 2008 and March 2012, 72 patients with stage III or IV MM were enrolled. Patients received in situ DNP alone (n=32) or in combination with laser therapy (n=32), and each group received dacarbazine chemotherapy. The levels of peripheral cluster of differentiation (CD)4+CD25+ regulatory T cells (Tregs), interleukin (IL)-10 and tumor growth factor (TGF)-ß were detected by ELISA. The association between delayed-type hypersensitivity (DTH) and survival time was evaluated. Although peripheral Treg levels significantly decreased over time in the two groups (P<0.001), there was no significant difference between the treatment groups (P=0.098). Patients receiving the combination treatment exhibited significantly higher interferon-γ production by CD8+ and CD4+ T cells (both P<0.001), as well as significantly reduced levels of IL-10, TGF-ß1 and TGF-ß2. In addition, patients in the combination treatment group experienced significantly longer overall survival (OS; P=0.024) and disease-free survival (DFS; P=0.007) times; a DTH response of ≥15 mm was also associated with increased OS time and DFS time (P≤0.001). Finally, no severe adverse events were observed in either treatment group. Overall, in situ immunization with DNP in combination with laser immunotherapy may activate focal T cells, producing a regional antitumor immune response that increases cell-mediated immunity and improves survival in MM patients. Thus, this may represent a novel therapeutic strategy for patients with unresectable, advanced MM.
RESUMEN
AIM: To explore the feasibility of RNA interference in the treatment of melanoma by inhibiting the Foxp3 gene expression in mouse B16 melanoma cells using RNA interference (RNAi) in vitro. METHODS: Small interfering RNA (siRNA) was designed according to Foxp3 gene. A short hairpin RNA (shRNA) lentivirus expression vector was constructed and transfected into mouse B16 cells, and RNA interference was induced in vitro. Western blot and real-time RT-PCR were performed to detect the expression of Foxp3 gene. ELISA was applied to detect the changes of TGF-ß(1);, TGF-ß(2);, IL-10 and other cytokines. The B16 cells after interference were co-cultured with CD4(+);CD25(-);T lymphocytes. CCK8 assay was used to monitor the proliferation of CD4(+);CD25(-);T lymphocytes. RESULTS: shRNA could suppress the expression level of Foxp3, down-regulate the inhibitory ability of tumor cells on the proliferation of CD4(+);CD25(-);T lymphocytes, and reduce the secretion of TGF-ß(1);, TGF-ß(2);, IL-10 and other cytokines, in particular the expression of TGF-ß(2);. CONCLUSION: RNA interference can inhibit the expression of target gene Foxp3 in mice melanoma cells and the proliferation of tumor cells. It can also reduce the inhibition on the proliferation of CD4(+);CD25(-);T lymphocytes, and the secretion of inhibitory cytokines.