STC1 is a Novel Biomarker Associated with Immune Characteristics and Prognosis of Bladder Cancer.

Background: Stanniocalcin-1 (STC1) is a well-studied oncogene that promotes different types of cancer progression. However, the expression status of STC1, the values of STC1 on prognosis, and its immune characteristic in bladder cancer (BLCA) have not been well examined.

Methods: The expression of STC1 and its clinicopathological as well as immune characteristics in BLCA samples were firstly identified in The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Immunohistochemistry (IHC) performed on the tissue microarray (TMA) slide was further used to validate the expression of STC1 and its relationship with immune features in 16 non-muscle invasive bladder cancer (NMIBC) samples and 42 muscle invasive bladder cancer (MIBC) samples.

Results: The expression of STC1 was upregulated in higher stage BLCA. High STC1 expression also predicted poor prognosis in BLCA. Subsequently, the TMA validated the expression and prognostic value of STC1 in BLCA. Bioinformatics analysis demonstrated that STC1 and common immune checkpoints as well as immune markers of various immune cells were positively correlated in TCGA. In addition, IHC data from the TMA further validated that tumor cells with higher STC1 level tended to express higher PDL1 as well as increased infiltration of CD3+ T cells.

Conclusion: To our knowledge, this is the first comprehensive study that investigates the clinical and immune characteristics of STC1 in BLCA. It may provide new insight into the function of STC1 in regulating tumor immune microenvironment. Further studies are warranted to uncover the potential mechanisms that mediate STC1 expression and tumor immunity in BLCA.