Evaluation of NANOG/HDAC1 Expression in Predicting Outcomes of BCG Therapy in Non‐Muscle Invasive Bladder Cancer

ABSTRACT Urinary bladder cancer includes non‐muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC). While patients with NMIBC have a better prognosis, NMIBC often recurs, requiring long‐term surveillance and repeated treatments. Intravesical Bacillus Calmette‐Guérin (BCG) therapy is standard for high‐grade or recurrent NMIBC; however, 30%–50% of patients failed to respond, and the mechanisms of resistance remain unclear. To identify predictive biomarkers for response to intravesical BCG therapy, we analyzed NANOG and Histone deacetylase 1 (HDAC1) expression in 90 bladder cancer specimens from NMIBC patients treated with BCG therapy using immunohistochemistry. The correlation between NANOG and HDAC1 expression and clinical outcomes, including response to BCG therapy, was assessed. High‐grade NMIBC cases showed significantly higher expression of NANOG and HDAC1 compared to low‐grade cases ( p < 0.05). Additionally, elevated NANOG expression in combination with HDAC1, was associated with poor response to BCG therapy and decreased lymphocyte infiltration in the tumor‐microenvironment. NANOG is suggested to directly increases HDAC1 expression, which could suppress lymphocyte infiltration in the tumor microenvironment by altering immune‐related gene expression. These findings suggest that the NANOG/HDAC1 axis plays a key role in predicting resistance to intravesical BCG therapy in NMIBC.