MITD1 deficiency leads to poor survival via tissue factor-mediated coagulation in bladder cancer.

BACKGROUND: Patients with cancer are at an increased risk of developing a hypercoagulative phenotype and venous thromboembolism. However, no clinical trial has yet confirmed that anticoagulant therapy improves cancer prognosis, and the mechanism underlying hypercoagulation in patients with bladder cancer is not well understood.

OBJECTIVES: We hypothesized that the prognostic genes affect tumor progression via tumor-mediated coagulation.

METHODS: We detected the most significant prognostic genes of bladder cancer with The Cancer Genome Atlas dataset, and validated them in two Gene Expression Omnibus and one ArrayExpress datasets. Immunohistochemical tests were performed on a cohort of 80 individuals to further examine the prognostic genes. For the most reliable prognostic gene, its influence on coagulation was evaluated with gene knockdown followed by next-generation sequencing and cellular and animal experiments.

RESULTS: Depletion of microtubule interacting and trafficking domain containing 1 (MITD1), a major prognostic gene of bladder cancer, significantly increased the tissue factor (TF) expression. MITD1 deficiency led to cytokinesis arrest, which, in turn, promoted the TF expression via unfolded protein response (UPR) and c-Jun. The knockdown of IRE1, an essential kinase of UPR, or the inactivation of c-Jun using c-Jun N-terminal kinase inhibitors weakened MITD1 deficiency- or dithiothreitol- induced TF upregulation. Cells lacking MITD1 promoted coagulation and metastasis in the experimental metastasis assay.

CONCLUSIONS: Our findings suggest the novel role of tumor prognostic genes upon the development of hypercoagulative phenotype and venous thromboembolism, thereby underlining the importance of anticoagulant therapy and shedding light on the therapeutic value of targeting MITD1 in bladder cancer.