Loss of opioid binding protein/cell adhesion molecule-like gene expression in gastric cancer.

Previous studies have reported that the expression of the opioid binding protein/cell adhesion molecule-like (OPCML) gene was frequently downregulated in various of types of cancer. However, little is known regarding the expression of the OPCML gene in gastric cancer. The present study identified that OPCML was downregulated in the gastric cancer SGC7901, KATO III, MKN45, MKN74, SNU1, AGS, N87 and a gastric mucosa cell line GES1, compared with normal gastric tissues by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). To investigate whether the downregulation of OPCML was due to promoter hypermethylation, the methylation of the OPCML promoter was assessed by methylation-specific polymerase chain reaction. Hypermethylation of the OPCML promoter was observed in the gastric cancer MKN45 cell lines, but was not as evident in normal gastric tissue. The methylation inhibitor 5-aza-2'-deoxycytidine was used to remove the methylation of the OPCML gene promoter, following which the expression of OPCML was restored. In addition, the function of the OPCML gene was studied in vitro, and it was found that the restoration expression of OPCML could lead to the suppression of cell growth. In conclusion, the present study has shown that OPCML, which acts as a tumor suppressor, was silenced in gastric cancer cell lines via aberrant hypermethylation of the promoter CpG islands, which may provide a novel molecular approach for the early diagnosis of gastric cancer.

Atorvastatin inhibits the 5-lipoxygenase pathway and expression of CCL3 to alleviate atherosclerotic lesions in atherosclerotic ApoE knockout mice.

BACKGROUND: The 5-lipoxygenase (5-LO) pathway and the chemokine CCL3 are involved in the inflammatory processes of atherosclerosis. Statins have shown cholesterol-independent pleiotropic effects on antiimmune and antiinflammatory responses in atherosclerosis. We postulated that this effect may be associated with the 5-LO pathway and CCL3. METHODS AND RESULTS: ApoE knockout mice were randomized into control group (normal diet), atherosclerosis group (high-cholesterol diet), and atorvastatin group (high-cholesterol diet and atorvastatin). Sixteen weeks later, aortic roots were stained with hematoxylin and eosin. Total cholesterol and low-density lipoprotein cholesterol were measured by the enzymatic methods. The gene and protein expressions of 5-LO and CCL3 were detected separately through real-time reverse transcription polymerase chain reaction and western blotting analyses. The serum levels of leukotriene B4 and leukotriene D4 were measured by enzyme-linked immunosorbent assay. All mice have atherosclerotic plaques, mice in the control group have only tiny atherosclerotic plaques, but mice in the atherosclerosis group and atorvastatin group have typical atherosclerotic plaques. The corrected plaque areas (plaque area/luminal area) of the aortas of mice in the atorvastatin group were significantly decreased compared with those of the atherosclerosis group. The serum cholesterol levels of the atorvastatin group were not of significant difference compared with those of the atherosclerosis group. The gene and protein expressions of 5-LO and CCL3 in the aortas, as well as the serum levels of leukotriene B4 and leukotriene D4 in atorvastatin group, were markedly reduced compared with those of the atherosclerosis group. CONCLUSION: These data suggested that atorvastatin significantly alleviated atherosclerotic lesions by inhibiting the 5-LO pathway and down regulating the expression of CCL3 in ApoE-/- mice.

Role of Krüppel-like factor 2 and protease-activated receptor-1 in vulnerable plaques of ApoE(-/-) mice and intervention with statin.

BACKGROUND: Krüppel-like factor 2 (KLF2) and protease-activated receptor-1 (PAR-1) are 2 novel factors that play important roles in inflammation and coagulation, yet their relationship with vulnerable plaques and statin remains uncertain. The purpose of this study was to explore the expression of KLF2 and PAR-1 in vulnerable plaques of ApoE gene knockout (ApoE(-/-)) mice and the pharmaceutical effect of statin on the expression of KLF2 and PAR-1. METHODS: ApoE(-/-) mice were randomized into an early-treatment group and a late-treatment group. Each group was randomized into 4 subgroups: normal diet control, high-fat diet control, high-dose statin, and low-dose statin. After 8 weeks of intervention with statin, the aortas were harvested to determine KLF2 and PAR-1 expression by semiquantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemical analyses. The relative area of plaque, the ratio of fibrous cap thickness to tunica intima/media thickness, and the vulnerability index of atherosclerotic plaques were calculated to evaluate plaque vulnerability. RESULTS: KLF2 increased whereas PAR-1 decreased in vulnerable plaques at messenger RNA, protein, and histologic levels. Atorvastatin increased KLF2 and decreased PAR-1 expression. CONCLUSIONS: Plaque vulnerability correlated negatively with KLF2 but positively with PAR-1. Upregulation of KLF2 and downregulation of PAR-1 could be direct or indirect effects of statin therapy.