Risk Factors and Nomogram for Postoperative Pulmonary Infection in Patients with Cervical Spinal Cord Injury.

OBJECTIVE: To identify the risk factors for developing postoperative pulmonary infection in patients with acute cervical spinal cord injury (CSCI), and to develop a nomogram prediction model. METHODS: Patients with CSCI who were admitted to 3 different medical centers between July 2011 and July 2021 were included in this study. All patients underwent cervical spine surgery. Data for patients admitted to the first 2 centers were included in a training set to establish the nomogram prediction model, and data for patients admitted to the third center were included in a validation set to externally verify the efficacy of the prediction model. For the training set, patients were divided into an infected group and a noninfected group (control group). Independent risk factors for postoperative pulmonary infection in patients with CSCI were identified by univariate and multivariate logistic regression analyses. Additionally, a nomogram prediction model was developed and validated based on the risk factors. RESULTS: A total of 689 patients were enrolled, including 574 for the training set and 115 for the validation set. Of the patients included for the training set, 144 developed pulmonary infection, with an incidence of 25.09%; 40 patients included for the validation set developed pulmonary infection (34.78%). Multivariate logistic regression analysis showed that age, American Spinal Injury Association grade, steroid pulse, high-level injury, smoking, multistage surgery, and operation duration were risk factors for the development of postoperative pulmonary infection in patients with CSCI. The area under the curve of the receiver operating characteristic curve of the model built by the training set was 0.905, and that of the receiver operating characteristic curve of the verification set was 0.917. The decision curve indicated that the model was in the range 1%-100%, and the predicted net benefit value of the model was high. CONCLUSIONS: Age, American Spinal Injury Association grade, steroid pulse, CSCI site, smoking history, number of surgical levels, and surgical duration are correlated with the development of postoperative pulmonary infection in patients with CSCI. The risk prediction model of postoperative pulmonary infection has a good prediction efficiency and accuracy.

Let-7i inhibits the malignant phenotype of osteosarcoma cells by targeting Aurora-B.

Our previous study indicated that Aurora-B is involved in osteosarcoma (OS) cell invasion and metastasis; however, the mechanism underlying Aurora-B overexpression in OS remains unknown. In the present study, significantly downregulated let-7i expression in OS tissues and OS cells was observed compared with that in normal adjacent tumorous tissues and human osteoblast cell lines. Bioinformatic predictions have revealed a conserved binding site in a microRNA locus on Aurora­B, suggesting the potential of let­7i targeting the Aurora­B gene. To validate this, a luciferase reporter assay was performed on OS cells. The results indicated that Aurora­B is a likely to be a direct target negatively regulated by let­7i. The expression of let­7i in OS cells was restored by infection with let­7i mimics. Results revealed that Aurora­B mRNA and protein expression levels were significantly decreased. Furthermore, the proliferation, migration and invasion abilities of OS cells were significantly suppressed by infection with let­7i mimics. Notably, the inhibitory effect of silencing Aurora­B by LV­shAurora­B on cell proliferation, migratory and invasive ability was significantly lower than that by let­7i mimics, which indicated that let­7i inhibits cell malignant phenotypes partially by targeting Aurora­B in OS cells. All data suggested that let­7i may be a novel potential target for OS treatment.

Knockdown of Aurora-B alters osteosarcoma cell malignant phenotype via decreasing phosphorylation of VCP and NF-κB signaling.

The aim of this study is to investigate the effects of inhibiting Aurora-B on osteosarcoma (OS) cell malignant phenotype, phosphorylation of valosin-containing protein (VCP), and the activity of NF-κB signaling in vitro. The expressions of Aurora-B and p-VCP proteins were detected by immunohistochemistry in 24 OS tissues, and the relationship between Aurora-B and p-VCP was investigated. The results showed that there was a positive correlation between Aurora-B and p-VCP proteins. The expression of Aurora-B in human OS cell lines U2-OS and HOS cells was inhibited by specific short hairpin RNA (shRNA) lentivirus (AURKB-shRNA lentivirus, Lv-shAURKB) which targeted Aurora-B. The results showed that the phosphorylation of VCP, the activity of NF-κB signaling pathway and the malignant phenotype of OS cells were all suppressed by knockdown of Aurora-B. It indicated that the inhibition of Aurora-B alters OS cells malignant phenotype by downregulating phosphorylation of VCP and activating of the NF-κB signaling pathway in vitro.

LY294002 inhibits the malignant phenotype of osteosarcoma cells by modulating the phosphatidylinositol 3­kinase/Akt/fatty acid synthase signaling pathway in vitro.

Increasing evidence suggests that fatty acid synthase (FASN) is crucial in the carcinogenesis of various types of tumor. In addition, the phosphatidylinositol 3­kinase (PI3K)/Akt signaling pathway, which is closely associated with cellular metabolism, affects cancer biology. However, whether the malignant phenotype of osteosarcoma (OS) cells is regulated by the PI3K/Akt/FASN signaling pathway and how the PI3K family specific inhibitor, 2­(4­morpholinyl)­8­phenyl­chromone (LY294002) affects the malignant phenotype of OS cells remains to be elucidated. In the present study, U2­OS and MG­63 cells were treated with LY294002 and subsequently western blot analysis was used to examine Akt, p­Akt and FASN protein expression. Additionally, FASN mRNA was detected by reverse transcription quantitative polymerase chain reaction. MTT and fluorescence­activated cell sorting assays were used to assess proliferation and apoptosis. Migration and invasion were investigated using wound healing and transwell invasion assays. The results demonstrated that LY294002 suppressed the PI3K/Akt/FASN signaling pathway. However, the malignant phenotypes of OS cells mentioned above were significantly inhibited. The present results indicated that LY294002 inhibits the malignant phenotype of OS cells via modulation of the PI3K/Akt/FASN signaling pathway in vitro and may be a new therapeutic strategy for the management of OS.

LY294002 suppresses the malignant phenotype and sensitizes osteosarcoma cells to pirarubicin chemotherapy.

Pirarubicin is frequently used in chemotherapy against tumors. However, clinical use is severely limited by the development of progressive dose-dependent cardiomyopathy and acquired drug resistance. LY294002 is a commonly used pharmacologic inhibitor, which selectively inhibits the phosphoinositide 3-kinase-AKT nexus. The aim of this study was to investigate the combined inhibitory effect of LY294002 and pirarubicin on human osteosarcoma (OS) cells in vitro. The inhibitory effect of LY294002 plus pirarubicin on U2-OS and MG-63 OS cell proliferation, apoptosis, migration and invasion was investigated by cell proliferation, wound healing and Transwell invasion assays. The results revealed that LY294002 and pirarubicin synergistically induced apoptosis, and inhibited the growth, migration and invasion of OS cells. This indicates that LY294002 enhanced the effects of pirarubicin on OS in vitro. LY294002 combined with pirarubicin may thus be a future therapeutic strategy in OS.

Knockdown of Aurora-B inhibits osteosarcoma cell invasion and migration via modulating PI3K/Akt/NF-κB signaling pathway.

Increasing evidences reveal that Aurora-B may be involved in metastasis of malignant tumor. In this study, we investigated the inhibitory effect of Aurora-B on invasion and migration of OS cells and the activity of PI3K/Akt/NF-κB signaling pathway in vitro. The expression of Aurora-B and p-Akt (Ser473) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between Aurora-B and p-Akt was investigated. The results showed that there was a positive correlation between Aurora-B and p-Akt protein expression. Furthermore, we down-regulated the expression of Aurora-B through a recombinant lentivirus (Lv-shAURKB). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. Results showed that silencing Aurora-B inhibited cell migratory and invasive ability of OS cells in vitro. Finally, knockdown of Aurora-B suppresses the activity of PI3K/Akt/NF-κB signaling pathway in OS cells. Our results indicated that knockdown of Aurora-B suppresses OS cells migratory and invasive ability via modulating the "PI3K/Akt/NF-κB" signaling pathway in vitro. The Aurora-B blocker may be a new therapeutic strategy in OS management.