Genome-scale analysis identifies SERPINE1 and SPARC as diagnostic and prognostic biomarkers in gastric cancer.

BACKGROUND: Gastric cancer (GC) is one of the most common types of malignancy and is associated with high morbidity and mortality rates around the world. With poor clinical outcomes, potential biomarkers for diagnosis and prognosis are important to investigate. OBJECTIVE: The aim of this study is to investigate the gene expression module of GC and to identify potential diagnostic and prognostic biomarkers. METHOD: Microarray data (GSE13911, GSE29272, GSE54129, and GSE79973), including 293 stomach tumor tissues and 196 normal tissues, were analyzed to identify differentially expressed genes (DEGs). DEGs were identified in four profiles by intersecting four overlapping subsets, including 90 downregulated and 45 upregulated DEGs in common. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway analyses have been showed that extracellular matrix was the most enriched signal pathway. Furthermore, hub genes were analyzed by protein-protein interaction network and clinical outcomes were assessed by Kaplan-Meier survival analysis. Two independent datasets were used to validate the differential expression of two hub genes: Serpin Family E Member 1 (SERPINE1) and Secreted Protein Acidic and Cysteine Rich (SPARC). RESULTS: Validation of independent datasets indicated that SERPINE1 and SPARC expression were drastically increased in gastric tumor tissues and associated with poor outcomes in GC patients. The expression of SERPINE1 was related to race (Asian and White) (P< 0.05). CONCLUSION: SERPINE1 and SPARC were significantly upregulated in gastric tissues and associated with poor outcomes. The investigations of SERPINE1 and SPARC may promote their predictive and prognostic value in GC.

EBV infection and MSI status significantly influence the clinical outcomes of gastric cancer patients.

BACKGROUND: Epstein-Barr virus (EBV) and microsatellite instability (MSI) are associated with the carcinogenesis of many kinds of tumors, including gastric cancer (GC). However, the impact of EBV and MSI status on the prognosis of stage II and III GC is still unclear. The aim of this study was to find out the prognostic value of EBV and MSI status in a population of GC patients from Southern China. METHODS: Patients were genotyped for EBV infection based on the detection of EBV DNA from the formalin-fixed paraffin-embedded (FFPE) specimens. Sequentially, MSI status was measured by direct sequencing. Clinical characteristics and overall survival (OS) were analyzed in 202 GC patients. Additionally, the association of EBV and MSI status with chemotherapy-based toxicity was analyzed in 324 GC patients. RESULTS: The survival analysis revealed EBV+ patients had a poorer OS than EBV- patients (HR=1.75, 95% CI: 1.08-2.82, FDR p=0.04). This survival advantage for EBV- patients was also found in patients <60y (FDR p=0.04) and patient with stage III disease (FDR p=0.04). CONCLUSIONS: EBV infection and MSI status are associated with overall survival of gastric cancer patients. However, traditional chemotherapy showed no difference on outcome of patients in EBV and MSI subgroups.

Propranolol induced G0/G1/S phase arrest and apoptosis in melanoma cells via AKT/MAPK pathway.

Both preclinical and epidemiology studies associate ß-adrenoceptors-blockers (ß-blockers) with activity against melanoma. However, the underlying mechanism is still unclear, especially in acral melanoma. In this study, we explored the effect of propranolol, a non-selective ß-blocker, on the A375 melanoma cell line, two primary acral melanoma cell lines (P-3, P-6) and mice xenografts. Cell viability assay demonstrated that 50µM-400µM of propranolol inhibited viability in a concentration and time dependent manner with an IC50 ranging from 65.33µM to 148.60µM for 24h -72h treatment, but propranolol (less than 200µM) had no effect on HaCaT cell line. Western blots showed 100µM propranolol significantly reduced the expression of Bcl-2 while increasing the expressions of Bax, cytochrome c, cleaved capase-9 and cleaved caspase-3, and down-regulated the levels of p-AKT, p-BRAF, p-MEK1/2 and p-ERK1/2 in melanoma cells, after a 24h incubation. The in vivo data confirmed the isolation results. Mice received daily ip. administration of propranolol at the dose of 2 mg/kg for 3 weeks and the control group was treated with the same volume of saline. The mean tumor volume at day 21 in A375 xenografts was 82.33 ± 3.75mm3vs. 2044.67 ± 54.57mm3 for the propranolol-treated mice and the control group, respectively, and 31.66 ± 4.67 mm3vs. 1074.67 ± 32.17 mm3 for the P-3 xenografts. Propranolol also reduced Ki67, inhibited phosphorylation of AKT, BRAF, MEK1/2 and ERK1/2 in xenografts. These are the first data to demonstrate that propranolol might inhibit melanoma by activating the intrinsic apoptosis pathway and inactivating the MAPK and AKT pathways.

Analysis of ABCG2 methylation in stool samples of Chinese healthy males by pyrosequencing.

ABCG2, an efflux pump protein-BCRP coding gene, is involved in the acquisition of chemotherapeutic drug resistance. In recent years, the epigenetic regulation of ABCG2, such as DNA methylation, has become a research hotspot and been attracting widespread attention. Methylation Special PCR (MSP) has been the mainly used method for gene methylation detection for a long time. With the development of pyrosequencing (PSQ) instrument and the convenience, simpleness, and economical benefit it brings, it will become the mainstream method for gene methylation detection in the near future. This study aims to establish a pyrosequencing method for detecting the methylation sites on ABCG2 gene promoter up-stream region, the promoter region and the first exon region, and to detect the methylation level of each site in stool samples, respectively. Thus, it cannot only lay the methodological foundation for the study of BCRP-mediated multi-drug resistance mechanisms in tumor cells, but also can give knowledge of ABCG2 methylation distribution in the intestine of Chinese healthy males by detecting the ABCG2 methylation levels in stool samples as the exfoliated intestinal epithelial cells constantly shed into the stool.

Marked Alteration of Rosuvastatin Pharmacokinetics in Healthy Chinese with ABCG2 34G>A and 421C>A Homozygote or Compound Heterozygote.

Rosuvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor used to lower blood low-density lipoprotein cholesterol, is a substrate of the membrane ABCG2 exporter. ABCG2 variants have been shown to alter rosuvastatin disposition. The objective of this study is to determine the impact of ABCG2 34/421 compound haplotypes on rosuvastatin pharmacokinetics in healthy Chinese volunteer subjects. Eight hundred healthy Chinese males were genotyped by polymerase chain reaction-pyrosequencing for ABCG2 34G>A, ABCG2 421C>A, SLCO1B1 521T>C, and CYP2C9*3 variants. Sixty-two male subjects with wild-type SLCO1B1 c.521TT and CYP2C9*3 were recruited for this pharmacokinetic study of rosuvastatin. A single oral dose of 10 mg rosuvastatin was administrated to each subject, and blood samples were collected before and at various time points after drug administration. Plasma concentration of rosuvastatin was determined by high-performance liquid chromatography-tandem mass spectrometry, and pharmacokinetic analysis was carried out using the WinNonlin program. In Chinese males, high allele frequency of ABCG2 c.34G>A (0.275) and c.421C>A (0.282) was observed, resulting in a considerable portion (23.3%) of subjects being ABCG2 34/421 compound heterozygotes. Compared with subjects with ABCG2 wild-type (c.34GG/421CC), plasma rosuvastatin Cmax and area under the curve, AUC0-∞, were significantly higher, while the apparent oral clearance, CL/F, was significantly lower in subjects with c.34AA, c.421AA, and c.34GA/421CA genotypes. Both t1/2 and Tmax were similar among subjects with different genotypes. A high frequency of ABCG2 c.34G>A and c.421C>A variants was present in Chinese males, and the disposition of rosuvastatin was significantly affected by both variants. These data suggest that it is advisable to genotype these variants when prescribing rosuvastatin to Chinese subjects, leading to a precise dose for each individual.