SOX9 expression in circulation and tumor site of lung cancer; diagnostic potential and demographic associations

BACKGROUND: Detecting the deregulation of transcription factors offers valuable insights into the causes of cancer, which can lead to personalized treatment strategies, improved outcomes, and better patient stratification. This study investigates the local and circulating expression profiles of SOX9, evaluates its diagnostic significance, and examines its correlations with the clinic-pathological features of lung cancer patients. METHODS AND RESULTS: The circulating level of SOX9 was measured using real-time PCR in lung cancer patients with various pathological characteristics, and results were compared to those from demographically matched healthy controls Peripheral blood mononuclear cells (PBMCs) served as a non-invasive and easily accessible source for analyzing SOX9 within a circulating cell population. SOX9 protein levels were assessed through immunohistochemistry, and the diagnostic values of SOX9 across different patient subtypes, as well as its correlation with clinic-pathological features, were evaluated. The data demonstrated that SOX9 was overexpressed in the PBMCs of lung cancer patients compared to healthy controls, consistent with its upregulation at the protein level in the tumor tissues of patients. The predictive value of SOX9 was particularly significant for lung tumors, with a strong positive correlation between SOX9 protein expression and metastatic status. The diagnostic potential of SOX9 gene levels in distinguishing lung cancer patients, including those with metastatic subtypes and those undergoing treatment, was found to be substantial. CONCLUSIONS: Our findings suggest that SOX9 expression in both circulating cells and tumor tissue may have significant value as a diagnostic marker for lung cancer. However, further validation in independent and prospective cohorts is needed to confirm its clinical utility.