The Effect Of Antisense Oligodeoxynucleotides Targeting Aurora A Kinase On Cell Proliferation And Chemosensitivity To Paclitaxel In Human Lung Cancer Cell Line A549

Part I The Effect of Antisense Oligodeoxynucleotides Targeting Aurora A Kinase on Tumor Growth and Changes of Cell Cycle in Human Lung Cancer Cell Line A549Background: Aurora kinases representing a family of evolutionarily conserved mitotic serine/threonine kinases have been found elevated in lung andenocarcinoma cell line A549. It is suggested that the overexpression of Aurora A contributes to the carcinogenesis, chromosomal instability (CIN), and de-differentiation of lung cancers.Objective: To address the possibility of Aurora A kinase as a therapeutic target for lung cancer, we employed the antisense oligodeoxynucleotides technique to inhibit Aurora A expression and investegated its effect on tumor growth and cell cycle of A549. Methods: Aurora A phosphorothioate antisense oligodeoxyneucleotides (ASODN) were synthesized and transfected into A549 cells by lipofectAMINE 2000.Aurora A mRNA and protein expression were examined by reverse transcription–polymerase chain reaction (RT-PCR) and Western blot respectively.Cell cycle distribution was observed by flow cytometer. MTT assay was used to evaluate cell inhibition ratio before and after transfection.Results: The proliferation of the A549 cells transfected with Aurora A ASODN was inhibited in a dose and time dependent manner. It is also observed that the IC50 of A549 cells after 48 hours'treatment of ASODN is about 300nmol/L and under such circumstances, the Aurora A mRNA and protein expression significantly decreased (P<0.05), along with the induction of accumulation of cells in S phase and the G2-M transition.Conclusions: Inhibition of Aurora A expression can results in the suppression of cell growth and G2-M arrest of human lung cancer cell line A549.Part II The Effect of Aurora A Antisense Oligodeoxyneucleotides on Chemosensitivity to Paclitaxel in Human Lung Cancer Cell Line A549 and its Possible MechanismsBackground: Paclitaxel inhibits cell cycle progression by compromising of spindle assembly and accumulating cells in G2/M phase and led to eventual apoptosis. Aurora A is essential in the assembly and stability of mitotic-spindle during mitosis. Therefore, it is plausible that paclitaxel and treatment against Aurora A may have a synergistic effect since they both target the same spindle.Objective: To explore the therapeutic role of targeting Aurora A kinase in lung cancer, we examined the effect of Aurora A antisense oligodeoxyneucleotides (ASODN) on chemosensitivity to paclitaxel (PTX) in lung cancer cell line A549, as well as discussed its possible mechanisms.Methods: PTX was given to each group after transfected with Aurora A ASODN for 6 hours, and continue to react for another 24 hours, the dose-effects response was observed by MTT assay and the value of IC50 was calculated in every group.Results: A549 cells showed the accumulation of cells in G2-M transition 24h and 48h after transfected with Aurora A ASODN. The cell inhibition ratio of the combination of Aurora A ASODN and paclitaxel was higher significantly than paclitaxel or Aurora A ASODN alone (both P<0.05).Conclusions: Inhibition of Aurora A expression can result in the suppression of cell growth and chemosensitizing activity to paclitaxel in human lung cancer cell line A549.