Knockdown of POLQ interferes the development and progression of hepatocellular carcinoma through regulating cell proliferation, apoptosis and migration.

BACKGROUND: DNA Polymerase Theta (POLQ) is a DNA polymerase involved in error-prone translesion DNA synthesis (TLS) and error-prone repair of DNA double-strand breaks (DSBs), whose function in hepatocellular carcinoma has not been investigated. METHODS: In the present study, both the data collected from the Cancer Genome Atlas (TCGA) and our group's results showed higher POLQ expression in HCC tissues than the para-cancerous tissues, which was associated with higher malignancy and poor prognosis. POLQ knockdown HCC cell model (shPOLQ) was constructed along with the corresponding negative control (shCtrl) through lentivirus infection for loss-of-function study. RESULTS: We found that, upon knockdown of POLQ, the proliferation and migration of HCC cells decreased and apoptosis percentage increased. Moreover, the percentage of cells in G2 phase significantly increased in shPOLQ group compared with shCtrl group. Xenografts in mice grafted with shPOLQ cells grew much slower than that transplanted with shCtrl cells, and expressed lower Ki67 level. Furthermore, an apoptosis-related signaling array was used to explore the involvement of downstream signaling pathways, suggesting the enhanced phosphorylation of HSP27 and JNK, and the de-activation of mTOR, PRAS40, ERK1/2 and STAT3 pathways. CONCLUSIONS: Collectively, our study revealed that POLQ may participate in the development of HCC, depletion of which may be a promising treatment strategy for HCC.

Inactivation of p53 in pterygium influence miR-200a expression resulting in ZEB1/ZEB2 up-regulation and EMT processing.

Loss of p53 function has been linked to progression of pterygium. MiR-200a is known to be controlled by p53. Here, we hypothesize that expression of miR-200a and downstream ZEB1/ZEB2 genes are regulated epithelial-mesenchymal transition (EMT) involved in the pathogenesis and recurrence of pterygium. For this study, 120 primary pterygial samples were collected. Immunohistochemistry and real-time RT-PCR were performed to determine the expression of p53, p53 down-stream EMT associated protein and miR-200a. The molecular correlation of p53, miR-200a and downstream genes were confirmed using primary pterygium cells (PECs). Expression of miR-200a in pterygium tissues was significantly lower than in conjunctiva controls (p = 0.015). Up-regulated miR-200a levels were positively correlated with and p53 protein expression (p < 0.001). The miR-200a downstream ZEB1/ZEB1 protein expression were negative correlated with miR-200a expression. Cell model studies demonstrated that miR-200a controlled the EMT of PECs through up-regulated ZEB1, ZEB2 and Snail gene expression. Our study demonstrated that inactivation of p53 in pterygium may influence miR-200a, resulting in ZEB1/ZEB2 up-regulation and EMT processing of pterygium. Therefore, we suggest that expression of miR-200a play an important role in EMT processing and recurrence of pterygium.

Endotoxin-induced acute lung injury in mice is protected by 5,7-dihydroxy-8-methoxyflavone via inhibition of oxidative stress and HIF-1α.

Up to date, the morbidity and mortality rates of acute lung injury (ALI) still rank high among clinical illnesses. Endotoxin, also called lipopolysaccharide (LPS), induced sepsis is the major cause for ALI. Beneficial biological effects, such as antioxidation, anti-inflammation, and neuroprotection was found to express by 5,7-dihydroxy-8-methoxyflavone (DHMF). The purpose of present study was to investigate the potential protective effects of DHMF and the possibile mechanisms involved in LPS-induced ALI. In our experimental model, ALI was induced in mice by intratracheal injection of LPS, and DHMF at various concentrations was injected intraperitoneally for 30 min prior to LPS administration. Pretreatment with DHMF inhibited not only the histolopatholgical changes occurred in lungs but also leukocytes infiltration in LPS-induced ALI. Decreased activity of antioxidative enzymes (AOE) such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) caused by LPS was reversed by DHMF. LPS-induced lipid peroxidation HIF-1α accumulation, NF-κB phosphorylation, and IκBα degradation were all inhibited by DHMF. In addition, LPS-induced expression of proinflammatory mediators such as TNF-α and IL-1ß were also inhibited by 5,7-dihydroxy-8-methoxyflavone. These results suggested that the protective mechanisms of DHMF on endotoxin-induced ALI might be via up-regulation of antioxidative enzymes, inhibition of NFκB phosphorylation, and HIF-1α accumulation. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1700-1709, 2016.

Vascular endothelial growth factor gene polymorphism and protein expression in the pathogenesis of pterygium.

BACKGROUND AND AIMS: Vascular endothelial growth factor (VEGF) gene expression has been linked to cancer progression. Here we hypothesise that the polymorphism and protein expression of VEGF are correlated with the pathogenesis and therapy response of pterygium. METHODS: 60 pterygial and 121 normal conjunctival samples were collected to determine the genotypes and protein expression of VEGF. Primary pterygium cells (PECs) were used to confirm the effect of the VEGF polymorphism on the angiogenesis of pterygium. RESULTS: 48 (83.3%) pterygial specimens tested positive for VEGF protein expression, which was significantly higher than in the control groups (16.7%, p<0.0001). The frequency of the 936 C>T variant, but not the -2578C>A variant, was significantly higher in the pterygium group compared with the control group. VEGF protein expression was significantly higher in the 936 C/C group than in the 936 C/T and T/T groups (p=0.001). The results of our cell model showed that PECs with the C/C genotype had a higher angiogenesis ability and higher response to the antiangiogenesis drug bevacizumab than cells with the C/T and T/T genotypes. CONCLUSIONS: We suggest that VEGF could be used as a target for pterygium therapy in patients with the 936C>T genotype.

CYP1A1 protein activity is associated with allelic variation in pterygium tissues and cells.

BACKGROUND: A thymine/cytosine point mutation in the MSP I restriction site of cytochrome P450 1A1 (CYP1A1) has been linked to susceptibility to smoking-related cancers and is reported to result in increased enzyme activity. Therefore, we sought to determine whether allelic variation of CYP1A1 is associated with protein expression and protein activity in pterygium. METHODS: We collected 150 pterygium samples and 50 normal conjunctiva samples, which served as controls. DNA samples were extracted from blood cells and then subjected to real-time ploymerase chain reaction (PCR) to determine CYP1A1 genotype. CYP1A1 protein expression was determined by immunohistochemical staining with a monoclonal antibody for CYP1A1. Pterygium epithelial cells (PECs), cultured in a serum-free culture medium, real-time PCR, western blot and enzyme-linked immunosorbent assay (ELISA) were used to understand the effect of CYP1A1 allelic variation in protein expression and activity. RESULTS: Forty-eight (33.3%) pterygium specimens tested positive for CYP1A1 protein expression. CYP1A1 protein expression was significantly greater in the pterygium group than in the control group (p<0.0001). In addition, CYP1A1 protein expression was associated with allelic variation. CYP1A1 protein expression was significantly greater in the m2/m2 group than in the m1/m1and m1/m2 groups (p=0.006). In the cell model, CYP1A1 protein expression and b[a]P 7,8-diol 9,10-epoxide (BPDE)-like DNA adducts increased in CYP1A1 m2/m2 (genotype T/T) PEC cells as compared with m1/m2 (genotype C/T) and m1/m1 (genotype C/C) cells. CONCLUSIONS: CYP1A1 expression in pterygium correlates with allelic variation and can be used as an independent risk marker.