Effect of a new antisense oligodeoxyribonucleotide, HA824, targeting at HER-2 mRNA on HER-2 expression

AIM: To observe specific effect of HA824, a new synthesized antisense oligodeoxyribonucleotide (ODN), HA824, targeting at HER-2 mRNA on HER-2 expression in SK-BR-3 breast cancer cells in mRNA and protein levels. METHODS: Antisense ODN HA824 targeting at HER-2 mRNA was synthesized as our previous description. Growth inhibition effect, mean(n = 3 - 5) 50% inhibitory concentrations (IC50) on proliferations of SK-BR-3 cells for HA824, HA4 and scramble were evaluated. HA824 on HER-2 mRNA and protein expression were examined by means of RT-PCR, flow cytometry and immunohistochemistry. RESULTS: The results indicated HA824 inhibited proliferation of SK-BR-3 cells in a dose dependent manner [IC50 (nmol · L-1): HA824, (47 ± 26); HA4, (97 ± 41); scramble, (251 ± 86). HA824 vs HA4, P < 0.05]. HA824 also significantly suppressed HER-2 mRNA and protein expression detected by RT-PCR, immunohistochemistry(HA824, light staining; HA4, moderate staining; scramble, heavy staining) and flow cytometry (fluorescence intensity: HA82A, 338.6; HA4, 355.5; scramble, 532.4). CONCLUSION: Not only can this kind of new synthesized antisense compound suppressed proliferation of SK-BR-3 breast cancer cells, but also specially inhibited HER-2 expression in mRNA and protein levels.