LAUSR

Lung cancer is the leading cause of cancer-related death worldwide, featuring a high incidence and low 5-year survival rate. Nearly 40% of patients are diagnosed with metastatic disease when they are first presented to the clinic. However, drug intervention targeting established metastatic tumors remains challenging, a better understanding of therapeutically exploitable mechanisms is urgently needed. This present study aims to explore novel therapeutic intervention against metastatic lung cancer. To understand the tumor-cell-intrinsic pathway that drives metastatic progression, we generated a highly invasive subline of lung cancer cell - A549 (ATCC, USA) by serial selections for Matrigel-coated transwells. The invasive subline A549-i3 shows about 5 times higher invasion potential than the parental cell line A549-Par (p<0.05, Student t-test). Colony-formation Assay and suspension growth in ultra-low attachment plates were used to measure the 2D proliferation ability and anoikis resistance, albeit with no difference. The differential efficacies between A549-Par and A549-i3 against multiple pathway inhibitors were screened using MTT assay in vitro. Notably, A549-i3 is more sensitive towards napabucasin (STAT3 inhibitor) and tipifarnib (FTase inhibitor) when compared with A549-Par, suggesting their potency in targeting cancer stemness and addicted oncogenic driver. Furthermore, napabucasin reduced the migration and invasion abilities of A549-i3 to similar extent as their parent counterpart. Overall, our preliminary data identified STAT3 as a potential therapeutic vulnerability in highly invasive cancer cells. Future work will be focused on identifying pathways responsible to sensitize highly invasive NSCLC cells toward STAT3 inhibition using multiomics approach. This project was supported by the Research Impact Fund (Ref. No.: R4015-19) from the Research Grants Council in Hong Kong. Citation Format: Sai Fung Yeung, Sze Man Chan, Chun Ho Law, Hoi Yin Chan, Kwok Wing Tsui. STAT3 activation promotes invasiveness and cancer stemness in lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6149.