Simvastatin is involved in radioresistance of esophageal cancer cells by regulating the PI3K/AKT pathway-mediated epithelial-mesenchymal transition / 西安交通大学学报(医学版)

Objective: To explore the role and mechanism of simvastatin in radioresistance and epithelial-mesenchymal transition (EMT) of esophageal cancer. Methods: Esophageal cancer cells were preconditioned with simvastatin (5 μmol/L) for 8 h, prior to exposure to x-ray irradiation. Clonogenic cell survival assay was performed to detect cell survival fraction. Cell proliferation was evaluated by MTT assay. Cell apoptosis was determined by flowcytometry. The activity of caspase-3 was detected by the common commercial kit. Additionally, Western blot assay was performed to analyze the activation of the PI3K/AKT pathway. Results: Pretreatment with simvastatin dramatically decreased the survival fraction (P<0.05) and proliferation (P<0.05) of the radiated cells, but aggravated cell apoptosis rate and caspase-3 activity (P<0.05). Furthermore, simvastatin stimulation significantly increased the expression of epithelial marker E-cadherin in 6 Gy-treated cells, but down-regulated the expression of mesenchymal marker N-cadherin and Vimentin (P<0.05). Mechanism analysis corroborated the activation of the PI3K/AKT pathway in cells after irradiation by elevating the expression of p-AKT, which was abrogated by simvastatin pre-treatment. More importantly, administration with IGF-1, an activator of PI3K/AKTpathway, attenuated the inhibitory effect of simvastatin on radioresistance and radiation-evoked EMT (P<0.05). Conclusion: Simvastatin inhibits radiation-induced EMT of esophageal cancer cells by blocking the PI3K/AKT pathway, and ultimately elevates the radiosensitivity, indicating a promising therapeutic avenue for treatment of esophageal cancer radioresistance.

A novel point mutation in CD18 causing leukocyte adhesion deficiency in a Chinese patient / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Leukocyte adhesion deficiency type 1 (LAD-1) is a rare, autosomal recessive inherited immunodeficiency disease characterized by recurrent severe bacterial infection, impaired pus formation, poor wound healing, associated with the mutation in the CD18 gene responsible for the ability of the leucocytes to migrate from the blood stream towards the site of inflammation. Correct and early diagnosis of LAD-1 is vital to the success of treatment and prevention of aggressive infections. The purpose of this study was to collect the clinical findings of the disease and to identify the genetic entity.</p><p><b>METHODS</b>CD18 expression in the peripheral blood leukocytes from the patient, his parents and normal control was measured with flow cytometry. The entire coding regions of the CD18 gene were screened with direct sequencing genomic DNA.</p><p><b>RESULTS</b>CD18 expression level on this patient's leukocyte surface was significantly decreased, with normal level in control group, his father and mother. Gene analysis revealed that this patient had a homozygous c.899A > T missense mutation in exon 8 of CD18 gene, causing the substitution of Asp to Val at the 300 amino acid. His parents were both heterozygous carriers while no such mutation was found in 50 normal controls.</p><p><b>CONCLUSION</b>This study disclosed a novel point mutation Asp 300 Val located in a highly conserved region (HCR) of CD18 and confirmed the heterogeneity of the mutations causing LAD-1, indicating it was quite beneficial to establish correct and early diagnosis in children with severe LAD-1.</p>

Comparison of surface marker of monocyte-derived dendritic cells between cord blood and adult peripheral blood / 上海第二医科大学学报

0.05).The percentage of CD40 positive cells in CBMC-derived DC was lower than that in PBMC-derived DC[(34.80?7.77)% vs(54.37?9.57)%,P