[Oncolytic property of HSV-1 recombinant viruses carrying the p53 gene].

ABSTRACT

OBJECTIVE: To obtain the recombinant herpes simplex virus 1 (HSV-1) inserted p53 gene with homologous recombination technology and investigate the virus' replication ability and oncolytic property in vitro and in vivo. METHODS: A eukaryotic expression case with p53 gene was cloned into pKO5/BN. The pKO5/p53 was constructed and transfected to the E. coli with pHSVΔIR-BAC by electroporation. Then the recombinant pHSVΔIR-BAC/p53 was obtained and transfected into Vero cells. Recombinant virus (MH1004) was identified by Southern blot and Western blot. Then the virus' replication abilities in several human tumors cells were tested by plaque assay. A murine melanoma model was established by subcutaneous inoculation of B16 cells. A dosage of 2×10(6) PFU (plaque forming unit) of MH1004, MH1001, HSV-1 wt or PBS was injected 3 times intratumorally in every 3 days. The tumor volume and survival rate were measured twice a week. RESULTS: The results of Western blot showed that the p53 protein can be detected from the Vero cells infected by MH1004. The replication abilities of MH1004 and HSV-1 wt in the same tumor cell was insignificant (P>0.05). And MH1004's replication abilities in SK-N-SH and U251 was significantly higher than other cancer cells. The tumors volume of group HSV-1 wt, MH1001(HSVΔIR)and MH1004 were (6 180±751), (5 760±267) and (4 850±532) mm(3) compared with PBS group (9 860±91) mm(3,) the difference of reduction of tumors volume was significant (P< 0.01). And the tumors volume of MH1004 group was smaller than HSV-1 wt and MH1001 group, but without significant difference (P>0.05). And the survival rate of MH1004 treated mice (5/6) was greatly higher than PBS (3/6), HSV-1 wt (3/6) and MH1001 (3/6). CONCLUSION: The replication abilities of MH1004 in neural tumor are very high and MH1004 can inhibit the growth of tumor so that prolong the survival of mice bearing murine melanoma.