Abstract
Lung cancer is one of the most prevalent types of cancer in the world. Surgery, chemotherapy and radiotherapy are used clinically as treatments for numerous cancers. Due to the appearance of drug resistance, the remission rate is limited to 40-50%. Docetaxel and pemetrexed are two drugs commonly used, and their effects in single-phase cell culture are well known. From the pharmacological point of view, it appears rational to hypothesize that sequential therapy effects can show better outcomes compared with traditional single-phase experiments. Considering this, the present study aimed to establish a first-line second-line adenocarcinoma treatment model, using the combination of cisplatin with docetaxel or pemetrexed in vitro in different sequential therapy timings. To test this, the human lung cancer A549 cell line was used. The inhibitory effect was determined by adding docetaxel following treatment with cisplatin and pemetrexed (Pem-Doc group) and comparing this with a group in which pemetrexed was added subsequent to treatment with cisplatin and docetaxel (Doc-Pem group). Additionally, the differences in the gene and protein expression levels of excision repair cross-completion gene 1 (ERCC1), a gene that promotes drug resistance to cisplatin, were compared between the two groups. The present results showed that the inhibitory effect of cell proliferation in the Pem-Doc group was increased compared with that of Doc-Pem group, while the gene expression and protein levels of ERCC1 in the Pem-Doc group were decreased compared with those of Doc-Pem group. The Pem-Doc treatment plan is more effective in inhibiting cell proliferation and in lowering the expression of the ERCC1 gene. Therefore, Pem-Doc may be a more effective adenocarcinoma treatment.