ABSTRACT
BACKGROUND: Studies have shown that the occurrence and development of T lymphocytic leukemia is related to the abnormality of Hedgehog pathway. The Smo gene is a key gene in this signaling pathway and controls the transmission of Hedgehog signaling into the cell membrane. OBJECTIVE: To design and screen a highly efficient and specific Smo-siRNA which is able to downregulate the Smo gene expression in Molt-4 cells, thereby inhibiting the Molt-4 cells proliferation and inducing apoptosis. METHODS: (1) Smo-siRNAs numbered 1, 2 or 3, and the scrambled non-siRNA control (SC) were obtained by chemosynthesis. Untreated and sc-treated cells were used as controls. (2) Smo expression levels in Molt-4 cells were analyzed using qRT-PCR at 24, 48, 72 hours after siRNAs delivered by NuclefectorTM.Cell proliferation in vitro was assayed by the cell counting kit-8.The morphology and percentage of apoptotic cells were revealed by Hoechst33258 staining and flow cytometry, respectively. RESULTS AND CONCLUSION: (1) Smo-siRNAs were successfully transferred into Molt-4 cells, and exhibited best silencing results. After transfection with Smo-siRNA1, the mRNA level of Smo was significantly reduced (P < 0.05), and the lowest level was at 48 hours after transfection. (2) Cell proliferation of Molt-4 cells was significantly inhibited by Smo-siRNA at 24 hours after transfection. (3) Hoechst staining results showed morphological changes of Molt-4 were in accordance with those of apoptotic cells. (4) The apoptotic rate was significantly increased in the Smo-siRNA group compared with the control group (P < 0.05). Findings from this study showed that suppression of Smo by RNA interference could effectively inhibit proliferation and induce apoptosis in Molt-4 cells, indicating that Smo-siRNA as gene targeted therapy or synergistic treatment has therapeutic potential in T-cell malignancies.