Role of FSCN1 in the tumor microenvironment of lung squamous cell carcinoma.

Tumor microenvironment (TME) regulated the development of the Lung squamous cell carcinoma (LUSC). To know more about the LUSC, this study tried to figure the role of fscin actin-bundling protein 1 (FSCN1) in the TME. We identified the FSCN1 as the hub immune gene in LUSC, with the use of weighted gene co-expression network analysis (WGCNA) and the Human Protein Atlas. Furthermore, we verified the higher expression of FSCN1 in LUSC compared with the normal tissues by quantitative reverse transcription PCR (qRT-PCR) and immunohistochemistry. We then explored the associations among FSCN1, immune infiltrations, and inflammatory factors with the use of Gene Expression Profiling Interactive Analysis (GEPIA) and Tumor IMmune Estimation Resource (TIMER). As a result, the expressions of FSCN1 was negatively related to the immune infiltrations, and positively related to the expressions of IL1A, IL1B, TGFB1 and TGFA. Moreover, we used the single-cell RNA-sequencing (scRNA-seq) data of LUSC to figure out the expressions level of FSCN1, IL1A, IL1B, TGFB1 and TGFA in the different cell type's of the TME. Finally, through the cytological experiments, we found that FSCN1 affected by TGFB1 contributes to the proliferation, anti-apoptotic effect, migration and invasion of the LUSC cells. In summary, this study Identified FSCN1 as the potential therapeutic target of LUSC, and reveals a complicated immune and inflammatory net in the TME.