Investigating acquired resistance in non-small cell lung cancer

Abstract

Introduction: Lung cancer is one of the leading causes of death in Malta, while 80% of all lung cancer cases are NSCLC. The EGFR is a crucial target in NSCLC as it signals several pathways of cell growth and proliferation. Third generation EGFR-TKI osimertinib inhibits the EGFR and in turn, inhibiting the growth of cancerous cells. Aim: To sensitize two adenocarcinoma cell lines, namely A549 (EGFR wild-type) and HCC827 (EGFR-mutant) by using osimertinib, a third generation EGFR-TKI. Methods: PrestoBlueÔ cell viability assays were carried out to evaluate the optimum concentrations of osimertinib on each cell line. Then, wound healing assays were carried out to assess the metastatic potential of each cell line treated with different concentrations of the third generation EGFR-TKI osimertinib. Results: A concentration-dependent decrease in percentage cell viability was observed in the A549 cell line. However, this was not the case with the EGFR-mutated HCC827 cell line, hence this cell line is resistant to osimertinib. The wound healing assays showed that osimertinib decreased the metastatic potential of the A549 cells. Conclusion: Osimertinib reduces proliferation and migration potential in the A549 adenocarcinoma cells but not in the HCC827 cell line, which reflects adenocarcinoma with an EGFR mutation. This research is a preliminary step to studying the effect of novel combinatory treatment with two ASOs for TCTP and HSP27. A combination which may possibly overcome the non-sensitivity seen by HCC827 to osimertinib, which may suggest resistance. Additionally, it can increase the effectiveness of osimertinib seen in A549 cells. Future work: The ALI model is mostly used to study NSCLC, especially when studying the pharmacological concepts. This 3D cell culture model mirrors the effects seen in vivo and the morphology and physiology of the cells are similar to what can be seen in vivo. These experiments are to be replicated in normal lung tissue cells and the cell cycle effects of the therapy are to be investigated using flow cytometry.