Evaluation of the relationship between follistatin-like protein 1, high mobility group box1, and osteopontin proteins in macrophage activation in non-small cell lung carcinoma

Objective: This study aimed to investigate the effects of endogenous proteins Follistatin-like Protein 1 (FSTL1), High Mobility Group Box1 (HMGB1), and Osteopontin (OPN) on macrophage polarization within the tumor microenvironment (TME) of non-small cell lung cancer (NSCLC). The role of these proteins in the TME and their influence on macrophage polarization markers were evaluated. Method: Tumor tissues and adjacent normal tissues were surgically collected from 15 patients diagnosed with non-small cell lung cancer (NSCLC). The mRNA levels of Follistatin-like Protein 1 (FSTL1), High Mobility Group Box1 (HMGB1), and Osteopontin (OPN) were quantified using quantitative real-time PCR (qRT-PCR). The expression of target proteins and macrophage polarization markers in tumor and adjacent normal tissues was assessed through immunohistochemistry (IHC). Additionally, the concentrations of these proteins in serum samples were quantified using ELISA. Results: A significant positive correlation was found between the protein expressions of FSTL1 and HMGB1 in tumor tissue (p=0.017). Furthermore, a positive relationship was observed between the M2 macrophage marker CD206 expression and tumor size (p=0.033). A negative correlation was noted between the mRNA expressions of FSTL1 and OPN (p=0.035). Additionally, a significant correlation was identified between the mRNA expression of HMGB1 and tumor size (p=0.002). Conclusion: The findings suggest that FSTL1, HMGB1, and OPN play significant roles in macrophage polarization and tumor size in NSCLC. The involvement of HMGB1 and CD206 in evaluating tumor size and as potential therapeutic targets is supported. Future studies should explore these proteins' synergistic effects and mechanisms in the TME to develop new clinical strategies.