Investigation of the effects of combination drug treatment with trastuzumab and 5-fluorouracil on A549 human lung cancer cell line

Lung cancer is one of the most common malignancies in the world and the leading cause of cancer-related death. In this study, we aim to investigate the effects of combining trastuzumab and 5-FU on the HER2-positive human non-small cell lung cancer cell line A549. A549 was cultured in RPMI medium with 10% FBS, 1% penicillin/streptomycin, at 37˚C in 5% CO2 incubator. MTT assay was performed to evaluate the effects of various concentrations of trastuzumab, 5-fluorouracil and combination. To determine the cytotoxic effect of drugs combination were used in survival assay (24-144h). The effect of Trastuzumab, 5-fluorouracil and combination were investigated by wound healing experiment, colony formation experiment and soft-agar experiment. Furthermore, caspase-3 caspase-7 and caspase-9 apoptotic proteins have been investigated. We observed that IC50 values for trastuzumab, 5-fluorouracil and combination by MTT assay 70µM, 75µM and 30µM-30µM respectively. Survival analysis showed that combination therapy significantly reduced cell viability. Combination theraphy were inhibited migration into the scratched area as compared to untreated cells. Furthermore, in soft agar and colony formation experiments, observed that combination treatments inhibit colony formation. While the levels of caspase-3 trastuzumab and 5-fluorouracil were increased, the combination of trastuzmab and 5-fluorouracil was reduced in the treated group. Caspase-7 level decreased in cells treated with trastuzumab. There was no significant change in the level of caspase-9. For the first time in the literature, it has been determined that the combination of trastuzumab-5-fluorouracil has an anti-proliferative effect on A549 cells. Further research is needed to clarify the mechanisms of combined treatment applications clearly.