[Experimental study on human pulmonary adenocarcinoma cell A549 transfected with HSV₁-TK gene in vitro and in vivo]

To observe killing effect of HSV₁-TK/GCV system on human pulmonary adenocarcinoma cell A549 in vitro and in vivo.

A retroviral vector containing TK gene was constructed and transduced into pulmonary adenocarcinoma cell A549 by electroporation. The sensitivity of transfected cell to GCV in vitro and bystander effect and cellular apoptosis were observed. The recombination and expression of TK gene were examined by DNA PCR and in situ hybridization individually. In addition, the therapeutic effect of GCV on subcutaneous tumors inoculated with transfected and parental cells respectively was observed.

The transfected cells were irregular in shape, polyangular and easy of vacuolization. The double time of A549,A549-PLXSN and A549-TK was 36.15±3.27,40.82±3.75 and 42.06±4.12 hours respectively (P>0.05). The sensitivity of transfected cells to GCV was 46 times higher than that of parental cells and bystander effect was more apparent in high density inoculation cells than in low density. Apoptotic bodies and semimoon feature in nuclear were observed in transfected cells, but not in parental cell. Apoptotic cells were found significantly more in transfected cells than in parental cells by FCM and TUNEL (P<0.001). The recombination and expression of TK gene were positive in the transfected cells. In vivo, growth of tumors which formed by transfected cells was significantly inhibited by GCV, however, there was no similar inhibitive effect found in control group.

The transfected cells have obtained sensitivity to GCV. The killing effect of TK/GCV system on tumor cells is probably related to apoptosis. GCV could inhibit growth of tumors inoculated by transfected cells.