Aberrant Methylation of Suppressor of Cytokine Signaling 1 (SOCS1) Gene as a Biomarker for Early Prediction and Diagnosis of Bladder Cancer.

Background: SOCS1 protein, the negative regulatory protein of the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling pathway, may inhibit signaling of JAK-STAT pathway by several cytokines and has tumor suppressor activity. Methylation of CpG island in the promoter region of SOCS1 gene has often been shown to inactivate the SOCS1 gene in certain human cancers. However, the precise role of SOCS1 in bladder cancer is unclear.

Methods: Two hundred forty-seven patients with BCa and 243 healthy controls were enrolled from Tumour Hospital Affiliated to Harbin Medical University, Hongqi Hospital Affiliated to Mudanjiang Medical University, and Mudanjiang Tumour Hospital from September 2013 to March 2019. The methylation rate in the promoter region of the SOCS1 among all participants were detected using the MassARRAY EpiTYPER system. A ROC curve was set out to analyze SOCS1 gene promoter CpG island methylation for BCa diagnosis.

Results: There was a significantly higher methylation rate in BCa compared to controls. Then we assessed the methylation rate of different CpG islands in SOCS1 gene among BCa cases and normal controls. Methylation rate was shown to vary among different CpG islands. The methylation rates of CpG islands were shown to vary among different grades. We observed that the methylation rate of different CpG islands vary according to pathological grades.

Conclusions: Our study demonstrates that aberrant methylation of CpG island in the promoter region of SOCS1 gene may be involved in occurrence, progression, and prognosis of BCa and, thus, may serve as an independent diagnosis and prognostic biomarker.