A Novel Camptothecin Analogue FL118 Shows Effectively Inhibition On Cisplatin Resistance Non-small Cell Lung Carcinoma

Objective: By observing the inhibition of new camptothecin analogs FL118 on proliferation, migration and resistance to cisplatin of cisplatin-resistant non-small cell lung cancer(NSCLC) cell lines, to discuss preliminary mechanism of FL118 effectiveness on A549 / DDP cells, then provide a theoretical basis for the treatment of FL118 on lung cancer drug resistance. Methods: MTT assay detected resistance index of A549 / DDP’s, Immunocytochemistry detected the expression of resistance proteins. The cell survival rate was detected by MTT assay, too; Wound healing scratch assay and transwell- matrigel invasion assay were used to detect the migratory and invasive capability; Immunocytochemistry and Western blot were assessed the expression of proteins P-gp, ERCC1, E-cadherin, Vimentin, and Survivin; Real-time PCR detected the expression of P-gp, ERCC1, E-cadherin, Vimentin and Survivin m RNA; The cell cycle were investigated by flow cytometry. Results: 1. Compared with the A549 cells, A549/DDP cells were fusiform, arranged in a spiral shape or radial, liked fiber cells. The resistance index of A549/DDP was 76.9(P <0.05). Immunocytochemistry revealed that the expression of resistance proteins P-gp, ERCC1 was significantly higher in A549/DDP. 2. Compared to the A549, FL118 also significantly inhibited growth of A549/DDP cells, and the inhibition showed a time- and concentration-dependent manner. At concentration of 100 n M, FL118 inhibiting effect starts significantly enhanced after 72h(P <0.05). 3. Wound healing scratch assay found that resistant cell migration declined after FL118 treatment(P<0.05). Transwell chamber experiments showed FL118 decreased drug-resistance cells invasion ability(P <0.05). And immunocytochemistry showed that the cell epithelial marker E-cadherin downregulation, mesenchymal marker Vimentin upregulation. 4. The Immunocytochemistry results showed Survivin protein expressed significantly in the A549/DDP compared with A549. After FL118 treatment, the expression of Survivin in A549/DDP decreased, and resistance proteins P-gp, ERCC1 expression was significantly reduced, the expression of E-cadherin increased, the expression of Vimentin decreased. 5. The Western blot results were consistent with the immunocytochemistry results. 6. Real-time PCR showed that, after treatment of FL118, gene expression of Survivin was decrease, and E-cadherin, Vimentin m RNA expressions were the same to proteins’. But expressions of resistance genes MDR1 and ERCC1 were not decrease. 7. Flow cytometry results showed that after FL118 treatment, A549 and A549 / DDP cells were arrested in S phase(P<0.05). Conclusion: FL118 made the cisplatin-resistant A549 / DDP cell cycle arrest in S phase through targeted inhibition of Survivin expression. FL118 inhibited the cisplatin-resistance non-small cell lung cancer cell growth effectively, and the inhibition rate was time and concentration-dependent. FL118 not only inhibited the cisplatin-resistant cells in metastatic potential, but also enhanced the sensitivity of resistant cells to FL118 by decreasing expression of resistance-associated proteins. It’s further defined the FL118 strong effect against drug-resistant and aggressive tumor. At the same time, FL118 could reverse the EMT phenotype of drug-resistant cells, suggesting new ideas on mechanisms of FL118 against drug-resistant tumor. The results provide new thinking for anticancer mechanism of FL118 researching, and provided a theoretical basis for the treatment of cisplatin resistance lung cancer.