Abstract

This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector pIZT/V5-His harboring the human IFN-λ2 gene. After the BmN cells were transfected with the pIZT/V5-His- hIFN-λ2 vector, the stably transformed BmN cells expressing hIFN-λ2 gene were selected using Zeocin. Following two months of screening, the transformed BmN cell line was obtained. Stable transformed BmN cell line can be maintained at a lower Zeocin concentration. The representing 26 kDa protein band of IFN-λ2 was detected by SDS-PAGE and Western blotting. The expression level of hIFN-λ2, determined by ELISA, was about 8.142 ng in 4 ´ 10⁵ cells. The antiproliferative activity of hIFN-λ2 was determined by MTT assay. The 50% inhibitory concentrations (IC₅₀) of the recombinant hIFN-λ2 on A549 (lung cancer cells), HL60 (acute promyelocytic leukemia cells), BEL-7402 (liver cancer cells) and M231 cells (breast cancer cells) were approximately 3.21, 2.84, 6.29 and 9.32 ng/ml, respectively. In summary, Human IFN-λ2 can be stably expressed in the transformed BmN cell line, and the expressed recombinant hIFN-λ2 demonstrated antiproliferative activity to tumor cells in vitro.

Key words: Human interferon-λ2 protein, gene expression, antiproliferative activity.