[Inhibitory effect of antisense oligodeoxynucleotides targeting HER-2 mRNA on growth of breast cancer: experiment in vivo with mice].
OBJECTIVE: To investigate the inhibitory effect of antisense oligodeoxynucleotides targeting HER-2 mRNA on growth of breast cancer. METHODS: Human breast cancer cells of the line SK-BR-3 that overexpresses HER-2 were injected subcutaneously into BALB/c nude mice. Seven to ten days after tumors were collected and made into homogenate. Antisense oligodeoxynucleotide HA6722 targeting HER-2 mRNA and its control sequence Scramble were synthesized. Forty-nine BALB/c nude mice were injected with homogenate of SK-BR-3 cells and then randomly divided into 7 equal groups: Group 1, injected intravenously with docetaxel (TXT) 7.5 mg.kg(-1).d(-1) once a week twice; Group 2, injected intravenously with TXT 15 mg.kg(-1).d(-1) once a week twice; Group 3, injected intravenously with TXT 7.5 mg.kg(-1).d(-1) once a week twice + HA6722 5 mg.kg(-1).d(-1) for 12 days; Group 4, injected intravenously with HA6722 5 mg.kg(-1).d(-1) for 12 days; Group 5, injected intravenously with TXT 7.5 mg.kg(-1).d(-1) once a week twice + Scramble6722 5 mg.kg(-1).d(-1) for 12 days; and Group 7, injected with normal saline. After the drug administration the mice were observed for additional 3-4 weeks to measure the size of tumor every other day. Then the mice were killed and the tumors were taken out to be examined. The inhibition rate was calculated. RESULTS: The inhibition rate of tumor in Group 3 was 88.3%, not significantly different from that in Group 2 (88.7%, P > 0.05). The inhibition rate in Group 4 was 76.3%. The inhibition rates of tumor of Groups 2, 3, and 4 were all significantly higher than that in Group 7. However, the inhibition rate of tumor of Group 6 was not significantly different from that in Group 7. CONCLUSION: Antisense oligodeoxynucleotides targeting HER-2 mRNA inhibits the growth of breast cancer in a sequence specific and dose-dependent manner.