We aimed to assess the antitumor selectivity and therapeutic potential of CNHK600-IL24 for breast cancer both in vitro and in vivo. Methods Cells
and cell culture Human embryonic kidney 293 (HEK293) cells were purchased from Microbix Biosystems. The human breast cancer cell line MDA-MB-231 and the normal fibroblast cell line MRC-5 were purchased from Shanghai Laboratory Animal Center, Chinese Academy of Sciences. HEK293 and MRC-5 cells were maintained in Eagle’s minimal essential medium (EMEM) supplemented with 10% fetal bovine serum (FBS), at 37°C, 5% CO2. MDA-MB-231 cells were cultured in Leibovitz’s L15 medium containing 10% FBS, at 37°C in CO2-free conditions. Construction and preparation of the oncolytic adenovirus CNHK600-IL24 The oncolytic adenovirus ZD55-IL24 was kindly
selleck kinase inhibitor provided by Professor Xin-yuan Liu from the Shanghai Institutes for Biological Sciences of the Chinese Academy of Sciences. Plasmid pXC1 was purchased from Microbix Biosystems Company, Canada. pClon9, pUC19-INS, SG502-△CR2 and the adenovirus backbone plasmid pPE3 were constructed by the Laboratory of Gene and Viral Therapy, Eastern Hepatobiliary Surgical Hospital, Second Military Medical University, KPT-8602 in vitro Shanghai. Restriction enzymes were purchased from New England Biolabs. Plasmid pCLON9 was digested with XhoI and SpeI, and pUC19-INS was digested with XbaI and SalI. The resulting 2680 bp and 1211 bp DNA fragments were ligated to create pCLON9-INS. The IL-24 expression cassette includes the human cytomegalovirus (hCMV) immediate-early promoter, the IL-24 gene and the SV40 PolyA sequence. before It was extracted from ZD55-IL24 by BglII digestion and inserted into pCLON9-INS, which was digested with
BamHI. The CB-839 supplier recombinant product was named pCLON9-INS-IL24 and sent to Shanghai GeneCore Biotechnologies Co. Ltd. for sequencing. After digestion with AgeI and NotI, SG502-ΔCR2 and pCLON9-INS-IL24 were ligated to form SG502-INS-IL24. To obtain the virus, the plasmid SG502-INS-IL24 and type 5 adenovirus pPE3 were cotransfected into HEK293 cells with Lipofectamine 2000 (GIBCO BRL). The recombinant virus was verified by repeated PCR amplification. The correct recombinant virus, named CNHK600-IL24, was amplified in 293 cells and purified by cesium chloride density gradient centrifugation. Oncolytic adenovirus CNHK600-EGFP, which carries enhanced green fluorescent protein (EGFP) as a reporter gene, was constructed and prepared in the same way. Median tissue culture infective dose method (TCID50) was used to determine the virus titer. Fluorescence microscopy MDA-MB-231 cells and MRC-5 cells were infected with CNHK600-EGFP at a multiplicity of infection (MOI) of 1 and observed under the fluorescence microscope. Photographs were taken 48 h, 72 h and 96 h after infection.