Down-regulation of granulocyte-macrophage colony-stimulating factor by 3C-like proteinase in transfected A549 human lung carcinoma cells.

BACKGROUND: Severe Acute Respiratory Syndrome (SARS) is a severe respiratory illness caused by a novel virus, the SARS coronavirus (SARS-CoV). 3C-like protease (3CLpro) of SARS-CoV plays a role in processing viral polypeptide precursors and is responsible of viral maturation. However, the function of 3CLpro in host cells remains unknown. This study investigated how the 3CLpro affected the secretion of cytokines in the gene-transfected cells. RESULTS: From immunofluorescence microscopy, the localization of c-myc tagged 3CLpro was detected both in the cytoplasm and nucleus of transfected A549 cells. Expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly decreased in 3CLpro-transfected cells by both RT-PCR and ELISA, but without changes in other cytokines, i.e., IL-1ß, IL-6, IL-8, IL12p40, TNF-α, and TGF-ß. Furthermore, the protein levels of NF-kB decreased in 3CLpro-transfected A549 cells when compared to EGFP transfected cells. CONCLUSIONS: Our results suggest that the 3CLpro may suppress expression of GM-CSF in transfected A549 cells through down-regulation of NF-kB production.

Toxicogenomics of A375 human malignant melanoma cells treated with arbutin.

Although arbutin is a natural product and widely used as an ingredient in skin care products, its effect on the gene expression level of human skin with malignant melanoma cells is rarely reported. We aim to investigate the genotoxic effect of arbutin on the differential gene expression profiling in A375 human malignant melanoma cells through its effect on tumorigenesis and related side-effect. The DNA microarray analysis provided the differential gene expression pattern of arbutin-treated A375 cells with the significant changes of 324 differentially expressed genes, containing 88 up-regulated genes and 236 down-regulated genes. The gene ontology of differentially expressed genes was classified as belonging to cellular component, molecular function and biological process. In addition, four down-regulated genes of AKT1, CLECSF7, FGFR3, and LRP6 served as candidate genes and correlated to suppress the biological processes in the cell cycle of cancer progression and in the downstream signaling pathways of malignancy of melanocytic tumorigenesis.

Urine interleukin-1beta in children with acute pyelonephritis and renal scarring.

AIM: Acute pyelonephritis is a common infectious disease in children and can result in permanent renal damage. Interleukin (IL)-1beta is an important inflammatory mediator that appears early during bacterial infection. This prospective study examined urine IL-1beta levels in children with acute pyelonephritis documented by (99m)Tc-dimercaptosuccinic acid (DMSA) scan, and also evaluated whether this cytokine correlated with renal scarring. METHODS: A total of 75 children aged 1-121 months with a diagnosis of first-time febrile urinary tract infection (UTI) were studied. The following inflammatory markers were assessed: fever, white blood cell (WBC), neutrophil, C-reactive protein (CRP) and urine IL-1beta. Urine samples were collected for IL-1beta measurement by enzyme-linked immunosorbent assay before and after antibiotic treatment of the infection. Follow-up DMSA scan was performed at 6-12 months after the acute pyelonephritis to detect renal scarring. Twenty children with other febrile illnesses served as non-renal febrile controls. RESULTS: The 75 children were divided into acute pyelonephritis (n = 41) and lower UTI (n = 34) groups according to the findings of DMSA scans. Fever, WBC count, neutrophil count and CRP were significantly higher in the children with acute pyelonephritis than in those with lower UTI (all P < 0.001). The initial urine IL-1beta levels of children with acute pyelonephritis were significantly higher when compared with lower UTI and non-renal febrile controls (P < 0.001). Urine IL-1beta in children with acute pyelonephritis was positively correlated with fever, CRP, WBC, neutrophil and leucocyturia. Renal scarring was found in 12 (29.3%) of the 41 children with acute pyelonephritis. The mean age was significantly lower in the children with renal scarring compared with those without (P < 0.05). CONCLUSION: These results have shown that urine IL-1beta level may serve as a useful marker for the early detection of acute pyelonephritis in febrile children. Young children are at a risk of the development of renal scarring following acute pyelonephritis.

Toxicogenomics of kojic acid on gene expression profiling of a375 human malignant melanoma cells.

Kojic acid is a natural product and normally used as a food additive and preservative, a skin-whitening agent in cosmetics, a plant growth regulator and a chemical intermediate. Using DNA microarray technology, the overall biological effects of kojic acid on the gene expression profiling of a human skin A375 malignant melanoma cells were examined. After treatment with kojic acid, a total of 361 differentially expressed genes were distinctively changed with 136 up-regulated genes and 225 down-regulated genes. We used the bioinformatics tool to search the gene ontology and category classification of differentially expressed genes that provided the useful information of expressed genes belonging to cellular component, molecular function and biological process in regulation of melanogenesis. Seven down-regulated genes of APOBEC1, ARHGEF16, CD22, FGFR3, GALNT1, UNC5C and ZNF146 that were typically validated by the real-time quantitative PCR (RT-qPCR) analysis technology showed to be the tumor suppressor genes in melanoma cancer cells. Thus, microarray technology coupled with RT-qPCR offered a high throughput method to explore the number of differentially expressed genes responding to kojic acid and their biological functions, and led to more understanding of kojic acid effects on skin cancer therapy and related side effects. Moreover, the differentially expressed genes may become useful markers of skin malignant melanoma for further diagnostic and therapeutic applications.