AIM: To study the EBV LMP-1 gene integrated in the chromosome of poorly differentiated nasopharyngeal carcinoma cell line SUNE-1. METHODS: The LMP-1 gene of SUNE-1 was detected with PCR; Deletion of LMP-1 was examined by restriction endonuclease analysis and PCR. The deletion was precisely localized by DNA sequencing. RESULTS: The LMP-1 gene integrated in the chromosome of SUNE-1 could be deleted or non-deleted. The two introns of LMP-1 gene were shown being lost in SUNE-1 cell line. CONCLUSION: Deletion of intron 1 and intron 2 happen in some of the LMP-1 gene integrated in the chromosome of SUNE-1.

Objective To study the acute toxicity of slow-release (poly lactic-co-glycolic acid) PLGA-gemcitabine microsphere and gemcitabine on mice.Methods Up and down procedure (UDP) was used to determine the median lethal dose (LD50) of PLGA-gemcitabine microsphere and gemcitabine on mice respectively.Results The LD50 of PLGA-gemcitabine microsphere on mice was 256.30 mg/kg,gemcitabine was 8.91 mg/kg.The difference was 28.8 times.Conclusion PLGA-gemcitabine microsphere can markedly reduce the acute toxicity of gemcitabine.