Role of phosphatidylinositol 3-kinase signaling pathway in radiation-induced liver injury.

Transforming growth factor-ß1 (TGF-ß1) is one of critical cytokines in radiation-induced liver injury. Hepatic stellate cells (HSC) are activated in the early stage of radiation-induced liver injury. However, it is currently unclear whether phosphatidylinositol 3-kinase (PI3K/Akt) signal pathway is activated in radiation-induced liver injury. Herein, male Sprague-Dawley rats were irradiated with 6 MV X-rays (30 Gy) on the right liver. Next, Hematoxylin and eosin staining, Masson staining, and electron microscopy were performed to examine pathological changes. Immunohistochemistry was performed to assess the expression of TGF-ß1, α-SMA, and p-Akt (S473) in liver tissues. In vitro, rat HSC cell line HSC-T6 cells were given different doses of 6 MV X-ray irradiation (10 and 20 Gy) and treated with LY294002. The expression of α-SMA and p-Akt in mRNA and protein levels were measured by reverse transcription-polymerase chain reactioin (RT-PCR) and Western blot. TGF-ß1 expression was detected by enzyme-linked immuno sorbent assay (ELISA). After irradiation, the liver tissues showed obvious pathological changes, indicating the establishment of the radiation-induced liver injury. Expression levels of TGF-ß1, α-SMA, and p-Akt (S473) protein in liver tissues were significantly increased after irradiation, and this increase was in a time-dependent manner, suggesting the activation of HSC and PI3K/Akt signal pathway. in vitro experiments showed that the TGF-ß1 secreted by HSCs, and the expression of Akt and α-SMA at mRNA and protein levels were significantly increased in irradiation groups. However, the expression of TGF-ß1, Akt, and α-SMA were significantly decreased in PI3K/Akt signal pathway inhibitor LY294002-treated group. Our results suggest that during radiation-induced liver injury, HSCs are activated by TGF-ß1-mediated PI3K/Akt signal pathway.

Screening of target genes in esophageal squamous cell cancer in Kazakh by oligonucleotide microarray / 中华消化外科杂志

Objective To screen the differentially expressed genes in esophageal squamous cell cancer (ESCC) and normal tissue of esophageal mucosa in Kazakh. Methods RNA was extracted from the ESCC sections in Kazakh patients, and was amplified to obtain cRNA. The gene expression profiles in ESCC and normal tissue of esophageal mucosa were detected by HG-U133 Plus 2.0 gene chip. The results were analyzed by bioinfor-matics. Results One hundred and seventy differentially expressed genes in ESCC and normal tissue of esophageal mucosa were found, with a difference of more than 10 times in expression levels. Of the 170 genes, 39 were up-regulated (signal log ratio > 3 ) and 131 down-regulated (signal log ratio < - 3). These factors such as cell cycle regulation, apoptosis, cytoskeleton; extracellular matrix, intracellular signal transduction, protein translation and synthesis, and immunological functions were correlated with the genes with abnormal expression. Conclusion The use of oligonucleotide microarray accurately and efficiently screen the 170 target genes in ESCC in Kazakh. It is suggested that these genes may be related to the carcinogenesis and development of ESCC in Kazakh.