The Inhibitory Effect Of Gene Transfer Of Recombinant P27mt Adenovirus On The Nude Mice Model Of Colorectal Carcinoma

Objective To explore the inhibitory effect of exogenous mutant type(mt) p27kipl gene (p27mt) on colorectal cancer in vivo by observing the growth and the growth inhibition ratio of tumor. Adenovirus-mediated p27mt was injected into nude mice with tumor, which were induced by colorectal cancer SW480 cell.Methods Human colorectal cancer SW480 cells were inoculated into the hypodermis of BalB/c nude mice through cell transplantation method. We established the nude mice model with colorectal cancer successfully. The nude mice with colorectal cancer were randomly divided into three groups, p27mt group, Lac-Z group and control group. Every group had nine nude mice. The number of nude mice model with colorectal cancer was twenty seven. Ad-p27mt(0.1ml), Lac-Z(0.1ml) and PBS(0.1ml) were injected into the tumor directly, respectively. Those drugs were injected every three days and three times totally. The longest and shortest diameter was measured every three days after injection. The average volume was calculated. The growth curve of tumor was drawn. Nude mice were executed by breaking their cervical vertebra after four weeks. Tumor was separated and weighted. The growth inhibition ratio of tumor was calculated. Unicell suspension was made for detection of apoptosis. Apoptosis of the tumor cells was measured.Results The latent phage of the growth of tumor was seven days to ten days. The average volume was about 0.5cm(0.48±0.23) in the fourteenth day. The percentage of forming tumor was 100%. No animals died after four weeks. Growth curve of tumor was significant between p27mt group versus control group(P<0.01), P27mt group versus Lac-Z group(P<0.01). There was no difference between control group and Lac-Z group(P>0.05). The inhibition ratio of tumor was 38.2%. There was significant difference between p27mt group versus control group(P<0.01), P27mt group versus Lac-Z group(P<0.01). There was no difference with control group versus Lac-Z group(P>0.05). Detection of apoptosis p27mt group was 42.8%, Lac-Z group was6.38%, Control group was 7.25%.There was significant difference between p27mt group and control group(P<0.01), P27mt group and Lac-Z group(P<0.01). There was no difference between control group and Lac-Z group(P>0.05).Conclusion Ad-p27mt gene therapy group could inhibit the growth of tumor markedly. Ad-p27mt had more stronger effect of promoting apoptosis. There was significant difference between p27mt group and control group (P<0.01), P27mt group and Lac-Z group(.P<0.01). Ad-p27mt gene significantly inhibited the growth of tumor of nude mice model of colorectal cancer in vivo.