Cxcl14

Immunohistochemistry assay was performed in human or mouse PC tumor tissues as previously described [21 (link)]. Briefly, tissues were sectioned into 4 μm thick sections from formalin-fixed and paraffin-embedded forms. After dewaxing, sections were incubated in 3% H₂O₂ solution for 30 min at room temperature to block endogenous peroxidase activities. Then, sections were microwaved for antigen retrieval in a citrate buffer. Sections were then incubated with primary antibodies CXCL14 (1 : 100), PD-L1 (1 : 100), and IL-10 (1 : 50) (Cell Signaling Technology, USA) at 4°C overnight. Slides were coverslipped after sample counterstaining. Five random regions in each section were selected to analyze under an inverted microscope. The cell images were analyzed by Image-Pro Plus 6 software (Media Cybernetics, USA).

Ninety-one formalin-fixed, paraffin-embedded archived surgical specimens of human prostate cancer were randomly selected for analysis by IHC. Antibodies were used at the following dilutions: 1:50 for YB-1 (Cell Signaling Technology, Danvers, MA, USA); 1:50 for EGFR (Abcam, Cambridge, MA, USA) and 1:50 for CXCL14 (Cell Signaling Technology, Danvers, MA, USA). A Discovery Auto-Stainer was employed to perform IHC according to the automated protocols (Ventana Medical Systems, Inc., Tucson, AZ, USA). The intensities of YB-1, EGFR and CXCL14 were determined by qualitative assessment of two levels: negative and positive. The intensity of YB-1, EGFR and CXCL14 staining was scored as: 0 (no staining), 1 (weak staining), 2 (moderate staining) or 3 (strong staining). The percentages of staining were scored as: 0: 0%, 1: 1–25%, 2: 26–50%, 3: 51–75%, and 4: 76–100%. A YB-1, EGFR and CXCL14 status (score ≤ 4) was defined as negative while scores > 4 represent positive. All proceedings have been conducted in compliance with the Human Genome/Gene Research Ethical Guidelines and were approved by the Ethics Committee of Sichuan Cancer Hospital (Approval Number SCCHEC-03-2018-005).