FKBP Prolyl Isomerase 11: A Novel Oncogene Interacting With SRSF1 in Esophageal Squamous Cell Carcinoma

ABSTRACT Esophageal squamous cell carcinoma (ESCC) is one of the main subtypes of esophageal carcinoma with high morbidity. This study aimed to explore the role of FKBP prolyl isomerase 11 (FKBP11) in ESCC and investigate the underlying mechanism. FKBP11 levels in ESCC tumor tissues and cell lines were measured. Cell function assays were conducted to evaluate the role of FKBP11 in ESCC cells. The xenograft mouse model was established to validate the effect of FKBP11 on ESCC tumorigenesis in vivo. The co‐immunoprecipitation assay was performed to determine the FKBP11‐interacting proteins. Obvious upregulations in FKBP11 expression were found in ESCC tumor tissues and cell lines. In vitro, FKBP11 knockdown weakened cell proliferation, migration, and invasion capacities and reinforced cell apoptosis in ESCC cells. In vivo, FKBP11 knockdown slowed ESCC tumorigenesis. The following mechanism investigation determined serine and arginine‐rich splicing factor 1 (SRSF1) as the FKBP11‐interacting protein in ESCC cells. FKBP11 directly bound to SRSF1 and FKBP11 knockdown decreased SRSF1 mRNA level. SRSF1 overexpression abrogated the inhibitory effect of FKBP11 knockdown on the proliferation and migration of ESCC cells. KBP11 functions as an oncogene in ESCC by targeting SRSF1.