(A537) Effect of IL-8 on Cutaneous Squamous Cell Carcinoma Proliferation and Migration

Introduction: Cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers worldwide and has the highest disease incidence in the head and neck. In recent years, there is increasing interest to develop targeted therapies capable of halting cSCC tumor progression or even trigger cancer regression. In our study, we aimed to profile the secretome of cSCC cells and examine the effects of one highly secreted cytokine on cancer cell proliferation and migration.

Methods: An established human cSCC (A431) and a primary human cSCC (HNA07) cell lines were cultured. Culture media was harvested on day 2 and a cytokine array was performed. One highly expressed cytokine (IL-8) was chosen for further investigation. To study cell proliferation, A431 cells were plated on a 96-well plate and 3 different concentrations of IL-8 were added. CellTiter-Glo assays were used to assess cell viability at hours 24 and 48. Two migration assays were performed. For the scratch migration assay, A431 cells were placed on a 24-well plate and allowed to grow to confluency. A scratcher comb was used to make uniform gaps in the cell monolayer. 3 concentrations of IL-8 were added to the wells, and the plates were incubated in a live-imaging microscope and imaged every 12 hours for 48 hours. For the transwell migration assay, a monolayer of cells was added to transwell inserts, which were fully submerged in media with or without IL-8. Cells were allowed to migrate for 12, 24, or 48 hours, stained with DAPI, and cells were counted using fluorescence microscopy.

Results: IL-8 was highly expressed by both A431 and HNA07. From the scratch migration assay, cells treated with 100 ng/ml of IL-8 had significantly faster gap closure at 12 and 24 hours compared to 10 ng/ml and 0 ng/ml. Additionally, cells exposed to 100 ng/ml of IL-8 migrated through the transwell membrane at a faster rate compared to negative controls at 12, 24, and 48 hours.

Conclusions: IL-8 is highly expressed by cSCC cells and enhances cancer cell proliferation and migration. Further investigation into the role of IL-8 within the tumor microenvironment may lead to a novel therapeutic approach for the treatment of cSCC.