2-methoxyestradiol is effective in 2D and 3D models of NCI-H2170 lung squamous cell carcinoma cells.

Lung squamous cell carcinoma (LUSC) is a difficult cancer to treat, with few targeted therapies to improve its poor prognosis. The goal of this study was to use a drug repurposing strategy to evaluate and compare drug sensitivities using 2D adherent and 3D spheroid models of NCI-H2170 LUSC cells. Both 2D adherent and 3D spheroid models were used to grow NCI-H2170 lung squamous cell carcinoma cells and evaluate their sensitivity to a large library of food and drug administration (FDA)-approved drugs, including many not typically used as anti-cancer agents. Cell death was assessed in the 2D adherent models, and for the top drugs half maximal effective concentration (EC50) values were determined. For the 3D spheroid models, drugs reducing spheroid size after 4 days of treatment were identified. There were 263 drugs that reduced the cell viability to <20% when cells were grown in 2D in 10 µM drug. When grown in 3D the cells were generally more drug resistant, with 87 drugs capable of reducing spheroid volume when grown over 4 days in 10 µM drug. Interestingly, 60 drugs proved effective in both model systems including many drugs that typically associated with anti-cancer properties. Of these 60, four were further found to have selective effects towards metastatic NCI-H2170 cells as compared to a much less metastatic matched cell line expressing the metastasis suppressor CREB3L1, in both 2D and 3D model systems. These included the hypoxia-inducible factor 1-alpha (HIF-1α inhibitor 2-methoxyestradiol, and three anti-infection agents (cetylpyridinium chloride, chlorhexidine-2HCl, zinc pyrithione).

conclusionsThese results suggest that the HIF-1α inhibitor 2-methoxyestradiol, and three anti-infection agents (cetylpyridinium chloride, chlorhexidine-2HCl, zinc pyrithione) may be effective for metastatic LUSCs.