Pneumonia promotes pulmonary metastasis of HCC after transplantation via VEGF regulated PI3K/AKT/Cas-9 signaling and angiogenesis

Abstract

Aim: Pneumonia is the most frequent early postoperative complication in liver transplantation (LT) recipients. Inflammation may provide a favorable environment for tumor implantation, so we aimed to evaluate the impact of pneumonia on pulmonary metastasis of hepatocellular carcinoma (HCC) and reveal its underlying mechanism. Methods: A training cohort with 234 LT recipients were recorded and analyzed. Using the propensity-score method, we matched covariates between patients with and without pneumonia. A model for predicting pulmonary metastasis was built and validated in an independent validating cohort containing 179 subjects. A mouse model was built to mimic HCC pulmonary metastasis. The potential pathway was revealed by cytokine array analysis and validated in vitro . Results: Pneumonia was an independent risk factor for pulmonary metastasis in liver transplant recipients. It promoted pulmonary metastasis in both the clinical setting and the mouse model. In vitro , LPS-stimulated VEGF secretion from macrophages in the lung significantly reduced cell apoptosis and activated PI3K/AKT/cas-9 signaling. Administration of VEGF receptor2 inhibitor Vatalanib could reduce metastasis and improve prognosis in pneumonia mice. Conclusion: Pneumonia promotes HCC pulmonary metastasis by activating PI3K/AKT/Cas-9 signaling in HCC cells via macrophage-originated VEGF. Vatalanib might be efficient in reducing HCC pulmonary metastasis in liver transplant recipients with pneumonia.