The role of FKBP51 in the prognosis of ulcerative colitis-associated colorectal cancer

Purpose: Ulcerative colitis (UC) carries a high risk of developing colorectal cancer (CRC). FK506-binding protein 51 (FKBP51) is a key regulator of glucocorticoid resistance and inflammatory tumor microenvironment. This study aimed to investigate the role of FKBP51 in UC-CRC prognosis. Materials and methods: The FKBP51 expression was measured by immunohistochemistry, qRT-PCR and western blot in control and tumor-containing tissues from UC-CRC patients. H&E staining was used to analyze the inflammatory status of each sample. The relationship between FKBP51 expression and UC-CRC prognosis was assessed by Kaplan-Meier curves and Mann-Whitney U test, and receiver-operating characteristic curves were generated to clarify the role of FKBP51 in predicting survival period and recurrence of UC-CRC patients. Results: The FKBP51 expression was significantly (p < 0.01) increased by 36.3% in tumor-containing tissues compared to control tissues in UC-CRC patients. Nuclear enrichment of FKBP51 in tumor-containing tissues was significantly (p < 0.001) increased by 78.5%. The UC-CRC patients with higher levels of FKBP51 expression ratio between tumor-containing tissues and control tissues had shorter survival periods, but greater neutrophil invasion and neutrophils to lymphocytes ratio (NLR) in peripheral blood. Moreover, the FKBP51 expression ratio was more helpful in predicting the survival periods and recurrence in the UC-CRC patients than the NLR in peripheral blood. Conclusions: The FKBP51 expression ratio between tumor-containing tissue and control tissue may be an important biomarker of inflammatory tumor microenvironment and more helpful for the UC-CRC prognosis.