ABSTRACT
Ubiquitin protein ligase E3 component n-recognin 5 (UBR5) has been identified as an oncogene in diverse cancers; however, whether its expression was associated with radiosensitivities of non-small cell lung cancer (NSCLC) cells remains unclear. Expression levels of UBR5 in NSCLC tissues and cell lines were examined by immunohistochemical staining and western blotting. Colony formation assay, CCK-8 cell viability assay, flow cytometry, and caspase-3 activity assay were performed to evaluate the radiosensitization of UBR5 knockdown in NSCLC cells, and the underlying mechanism in vitro was also investigated. UBR5 was highly expressed in NSCLC tissues, and its high expression was associated with the poor prognosis in 50 patients with NSCLC. After X-ray irradiation, the protein expression levels of UBR5 were also increased in NSCLC cells. UBR5 inhibition enhanced the radiosensitivity of NSCLC cells by inhibiting the cell viability and inducing apoptosis. Further investigation indicated that UBR5 knockdown-mediated radiosensitization involved the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway. Knockdown of UBR5 radiosensitizes NSCLC cells via the inactivation of the PI3K/AKT signal, which provided a novel therapeutic target for NSCLC radiosensitization.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Signal Transduction , Ubiquitin-Protein Ligases , Apoptosis , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/radiotherapy , Cell Line, Tumor , Cell Proliferation , Humans , Lung Neoplasms/genetics , Lung Neoplasms/radiotherapy , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Radiation Tolerance , Ubiquitin-Protein Ligases/geneticsABSTRACT
AIMS: Dihydroartemisinin has been shown to inhibit the development of pulmonary fibrosis in rats, but its mechanism has yet to be elucidated. This study aimed to determine the mechanisms of dihydroartemisinin in bleomycin-induced pulmonary fibrosis in a rat model. MAIN METHODS: Morphological changes and collagen deposition were analyzed via hematoxylin-eosin staining and Masson staining and the expression of biotic-factor-related oxidative stress in lung tissues was assayed with standard assay kits. The expressions of α-SMA, E-cadherin, and Nrf2/HO-1 were detected by Western blot and RT-PCR, and the cell morphology and proliferation of cultured type II alveolar epithelial cells (AECs) were assessed via microscopy and immunocytochemical assay. KEY FINDINGS: Dihydroartemisinin treatment significantly decreased the level of oxidative stress and collagen synthesis and inhibited AECs differentiation in bleomycin-induced pulmonary fibrosis compared to the control group (Pâ¯<â¯0.001). SIGNIFICANCE: Our results indicated that dihydroartemisinin might decrease oxidative damage to attenuate lung injury and fibrosis.
