人hIL-24Δ103重组腺病毒感染诱导A549细胞凋亡

hIL-24Δ103 Recombinant Adenovirus Infection Induces Apoptosis in A549 Cells

白细胞介素24(interleukin24,IL-24)是近年来新发现的1个IL-10家族细胞因子,具有明显的抗肿瘤活性.为了研究开发高活性、低分子量的IL-24,并探讨其用于肿瘤靶向治疗的可能性,本研究在前期基础上,进一步构建并制备了缺失N端103个氨基酸残基的IL-24(hIL-24Δ103)重组腺病毒,并观察了其对A549细胞生长增殖和凋亡的影响.首先,采用PCR技术扩增IL-24第104位至第206位氨基酸区域的编码序列,制备hIL-24Δ103重组腺病毒.用Ad-hIL-24Δ103重组腺病毒感染肺癌A549细胞.MTT分析结果表明,Ad-hIL-24Δ103感染显著抑制了A549细胞的生长.Hoechst 33258染色和流式细胞仪分析结果表明,Ad-hIL-24Δ103感染导致细胞凋亡.Western印迹分析结果表明,Ad-hIL-24Δ103感染导致了PKR和eIF-2α蛋白的表达上调与磷酸化激活,提示PKR和eIF-2α参与了hIL-24Δ103导致的细胞生长抑制和细胞凋亡过程的调节.

Interleukin 24 （IL-24） is a novel member of IL-10 cytokine family which has a significant anti- tumor activity. To investigate the therapeutic potential of novel IL-24 with low molecular weight and high activity in cancer treatment, we constructed the recombinant adenovirus expression vector of N-terminal truncated hIL-24Δ103 （amino acid residues 104-206）, and determined its effects on the cellular proliferation and apoptosis in A549 cells. The IL-24 encoding region for residues 104-206 was amplified by PCR, cloned into pMD18-T vector and then subcloned into pAdTrack-CMV shuttle vector. The recombinant adenovirus of hIL-24Δ103, namely Ad-hIL-24Δ103, was prepared in HEK293 cells according to the standard protocol, and subsequently used for viral infection in A549 lung cancer cells. MTT assay revealed that the infection with Ad- hIL-24Δ103 caused a significant growth inhibition in A549 cells. Hoechst 33258 staining and FACS analysis showed that the Ad-hIL-24Δ103 infection also resulted in an apparent induction of apoptosis in A549 cells. Additionally, immunoblotting analysis demonstrated that PKR as well as its downstream target eIF-2α were upregulated and phosphorylated in Ad-hIL-24Δ103 infected A549 cells, suggesting that PKR might play an important role in IL-24Δ103-induced apoptosis and cellular growth inhibition. The results demonstrated that adenovirus-mediated IL-24Δ103 expression inhibits cellular proliferation and induces apoptosis in A549 cells, which might serve as an attractive therapeutic agent in cancer treatment.