Weijia Fang

Celastrol induces apoptosis in non-small-cell lung cancer A549 cells through activation of mitochondria- and Fas/FasL-mediated pathways.

Celastrol is a natural compound extracted from the traditional Chinese medicinal herb, Tripterygium wilfordii Hook. It has attracted interests for its potential anti-inflammatory and antitumor effects. However, the molecular mechanisms of celastrol-induced apoptosis in cancer cells remain unclear. In this study, we investigated the effects of celastrol on the human non-small-cell lung cancer (NSCLC) cell line A549 in vitro. Celastrol caused a dose- and time-dependent growth inhibition of A549 cells with an IC(50) of 2.12 μM at 48 h treatment. Celastrol induced A549 cells apoptosis as confirmed by annexin V/propidium iodide staining and DNA fragmentation. Celastrol-induced apoptosis was characterized by cleavage of caspase-9, caspase-8, caspase-3, and PARP protein, increased Fas and FasL expression, and a reduction in the mitochondrial membrane potential. Furthermore, celastrol induced the release of cytochrome c. Celastrol also up-regulated the expression of pro-apoptotic Bax, down-regulated anti-apoptotic Bcl-2, and inhibited Akt phosphorylation. These results demonstrate that celastrol can induce apoptosis of human NSCLC A549 cells through activation of both mitochondria- and FasL-mediated pathways.

Rapid molecular identification of Listeria species by use of real‐time PCR and high‐resolution melting analysis

Identification of Listeria species via a molecular method is critical for food safety and clinical diagnosis. In this study, an assay integrating real-time quantitative PCR (Q-PCR) with high-resolution melting (HRM) curve analysis was developed and assessed for rapid identification of six Listeria species. The ssrA gene, which encodes a transfer-messenger RNA (tmRNA) is conserved and common to all bacterial phyla, contains a variable domain in Listeria spp. Therefore, Q-PCR and a HRM profile were applied to characterize this gene. Fifty-three Listeria species and 45 non-Listeria species were detected using one primer set, with an accuracy of 100% in reference to conventional methods. There was a 93.3% correction rate to 30 artificially contaminated samples. Thus, Q-PCR with melting profiling analysis proved able to identify Listeria species accurately. Consequently, this study demonstrates that the assay we developed is a functional tool for rapidly identifying six Listeria species, and has the potential for discriminating novel species food safety and epidemiological research.

Detection of let-7a MicroRNA by Real-time PCR in Colorectal Cancer: a Single-centre Experience from China

Colorectal cancer, a heterogeneous disease arising from a complex series of molecular changes, is one of the worlds leading causes of cancer deaths. MicroRNAs (miRNAs), an extensive class of small non-coding RNAs, have been implicated in cancer development and progression. One of the first miRNAs to be identified was let-7 miRNA, which has recently been found to be expressed at reduced levels in human lung cancer cells. We used a rapid stem-loop reverse transcription polymerase chain reaction method to quantify human let-7a miRNA expression in samples of human colorectal cancer. This method was able to detect let-7a miRNA in as little as 0.05 ng of total RNA from colorectal mucosa and its specificity was high (100%). Our results showed that the expression of let-7a miRNA was considerably reduced in two of eight patients. To our knowledge, this is the first study of Chinese patients to show reduced expression of endogenous let-7 miRNA in colorectal cancer.

Prognostic Value of Perineural Invasion in Gastric Cancer: A Systematic Review and Meta-Analysis

Background The prognostic role of perineural invasion in gastric cancer is controversial. Here, we present a systemic review and meta-analysis of the association between perineural invasion and survival in resectable gastric cancer patients. Methods A comprehensive literature search for relevant reports published up to April 2013 was performed using PubMed, Embase, Web of Science and Wanfang Data. Studies that investigated the role of perineural invasion with a sample size greater than 100 were included and analyzed. Results A total of 30,590 gastric cancer patients who had undergone curative gastrectomy from twenty-four studies were included. The median rate of perineural invasion positive was 40.9% (6.8%–75.6%). Fourteen studies investigated overall survival unadjusted for other variables in 23,233 gastric cancer patients. The relative hazard estimates ranged from 0.568–7.901 with a combined random effects estimate of 2.261 (95% CI = 1.841–2.777, P = 0.000). The effect of perineural invasion on overall survival adjusted for other prognostic factors was reported in 17 studies incorporating 8,551 cases. The hazard estimates ranged from 0.420–8.110 with a pooled random effects estimates of 1.484 (95% CI = 1.237–1.781, P = 0.000). There was heterogeneity between the studies (Q = 49.22, I-squared = 67.5%, P = 0.000). Disease-free survival was investigated adjusted in four studies incorporating 9,083 cases and the pooled fixed hazard ratio estimate was 1.371(95% CI = 1.230–1.527, P = 0.000). Conclusion Perineural invasion is an independent prognostic factor affecting overall survival and disease-free survival of gastric cancer patients who had undergone the curative resection. This effect is independent of lymph node status, tumor size and the depth of invasion as well as a range of other biological variables on multivariate analysis. Large prospective studies are now needed to establish perineural invasion as an independent prognostic marker for gastric cancer.

Molecular Epidemiology of Clostridium difficile Infection in Hospitalized Patients in Eastern China.

ABSTRACT Few studies on risk factors for and transmission of Clostridium difficile infection (CDI) in China have been reported. A cross-sectional study was conducted for 3 years in eastern China. Consecutive stool specimens from hospitalized patients with diarrhea were cultured for C. difficile. C. difficile isolates from these patients then were analyzed for toxin genes, genotypes, and antimicrobial resistance. A severity score for the CDI in each patient was determined by a blinded review of the medical record, and these scores ranged from 1 to 6. A total of 397 out of 3,953 patients (10.0%) with diarrhea were found to have CDI. Severity of CDI was mild to moderate, and the average (± standard deviation) severity score was 2.61 ± 1.01. C. difficile was isolated from stool specimens in 432 (10.9%) of all the patients who had diarrhea. C. difficile genotypes were determined by multilocus sequence analysis and PCR ribotyping; sequence type 37 (ST37)/ribotype 017 (RT017) (n = 68, 16.5%) was the dominant genotype. Eleven patients (16.2%) with this genotype had a CDI severity score of 5. Overall, three RTs and four STs were predominant; these genotypes were associated with significantly different antimicrobial resistance patterns in comparison to all genotypes (χ2 = 79.56 to 97.76; P < 0.001). Independent risk factors associated with CDI included age greater than 55 years (odds ratio [95% confidence interval], 26.80 [18.76 to 38.29]), previous hospitalization (12.42 [8.85 to 17.43]), previous antimicrobial treatment within 8 weeks (150.56 [73.11 to 310.06]), hospital stay more than 3 days before sampling (2.34 [1.71 to 3.22]), undergoing chemotherapy (3.31 [2.22 to 4.92]), and undergoing abdominal surgery (4.82 [3.54 to 6.55]). CDI is clearly a problem in eastern China and has a prevalence of 10.0% in hospitalized patients. Among risk factors for CDI, the advanced age threshold was younger for Chinese patients than that reported for patients in developed countries.

Clostridium difficile carriage in hospitalized cancer patients: a prospective investigation in eastern China.

BackgroundClostridium difficile carriage has been considered as a potential source for the deadly infection, but its role in cancer patients is still unclear. We aimed to identify the clinical and immunological factors that are related to C. difficile carriage in Chinese cancer patients.MethodsA total of 400 stool samples were collected from cancer patients who received chemotherapy in three hospitals of eastern China. Bacterial genomic DNA was extracted and two toxin genes (tcdA and tcdB) were detected. PCR ribotyping was performed using capillary gel electrophoresis. Concentrations of prostaglandin E2 (PGE2), transforming growth factor beta (TGF-β) and interleukin-10 (IL-10) were measured using enzyme-linked immunosorbent assay (ELISA) kits.ResultsEighty-two (20.5%) samples were confirmed to be C. difficile-positive and positive for tpi, tcdA, and tcdB genes. The C. difficile-positive rates in patients with diarrhea and no diarrhea were 35% and 19.7%, respectively (p = 0.09). Patients who were younger than 50 years old and were hospitalized for at least 10 days had a C. difficile-positive rate as high as 35%. In contrast, patients who were older than 50 years old and were hospitalized for less than 10 days had a C. difficile-positive rate of only 12.7% (p = 0.0009). No association was found between C. difficile carriage and chemotherapy regimen, antibiotic drug use, or immunosuppressive mediators, such as prostaglandin E2 (PGE2), transforming growth factor beta (TGF-β), or interleukin-10 (IL-10). Twelve ribotypes of C. difficile were identified, but none of them belonged to ribotype 027.ConclusionsWe conclude that younger patients and those with longer hospitalization stays may be more prone to C. difficile carriage. Studies of larger populations are warranted to clarify the exact role of C. difficile carriage in hospitalized cancer patients in China.

Identifying the clonal origin of synchronous multifocal tumors in the hepatobiliary and pancreatic system using multi-omic platforms

Synchronous multifocal tumors often pose a diagnostic challenge for oncologists. The purpose of this study was to determine the clonal origin and metastatic relationship of synchronous multifocal tumors in the hepatobiliary and pancreatic system using multi-omic platforms. DNA samples were extracted from three masses harvested from a 50-year-old Han Chinese male patient who suffered from synchronous multifocal tumors in the pancreatic tail, upper biliary duct, and omentum at the time of diagnosis. The clonal origin of these samples was tested using two platforms: next-generation sequencing (NGS) of 390 key genes harboring cancer-relevant actionable mutations and whole-genome copy number variation (CNV) chip analysis. The NGS approach revealed high mutational concordance, and the gene CNV profiles were similar between lesions. Whole-genome CNVs for the three samples were further investigated using an Affymetrix chip. Using matched CNV chip data from The Cancer Genome Atlas (TCGA), we developed a computational model that generated tissue-specific CNV signatures for hepatocellular carcinoma, pancreatic carcinoma, and cholangiocarcinoma to accurately identify the origin of the tumor samples. After adding the patients CNV chip data to the model, all three samples were clustered into the pancreatic cancer branch. Both our NGS and CNV chip analyses suggested that clinically diagnosed synchronous pancreatic cancer and cholangiocarcinoma originated from the same cell population in the pancreas in our patient. This study highlights the use of genomic tools to infer the origin of synchronous multifocal tumors, which could help to improve the accuracy of cancer diagnosis.

Aberrant Expression of HOXA5 and HOXA9 in AML

BACKGROUND Aberrant expression of HOX gene expression has been observed in cancer. The purpose of this study was to investigate the alteration of HOXA5 and HOXA9 expression and their clinical significance in acute meloid leukemia (AML). MATERIALS AND METHODS The expression of HOXA5 and HOXA9 genes of bone marrow samples from 75 newly diagnosed AML patients and 22 healthy controls for comparison were examined by Real- time quantitative PCR (RQ-PCR) assay. Statistical analysis was conducted to evaluate HOXA5 and HOXA9 expression as possible biomarkers for AML. RESULTS The results showed that the complete remission rate (52.6%) of the patients who highly expressed HOXA5 and HOXA9 was significantly lower than that (88.9%) in patients who lowly express the genes (P=0.015). Spearmann correlation coefficients indicated that the expression levels for HOXA5 and HOXA9 genes were highly interrelated (r=0.657, P<0.001). Meanwhile, we detected significant correlations between HOXA9 expression and age in this limited set of patients (P=0.009). CONCLUSIONS The results suggest a prognostic impact of increased expression of HOXA5 and HOXA9 in AML patients.

Genome Sequence and Analysis of Peptoclostridium difficile Strain ZJCDC-S82

Peptoclostridium difficile (Clostridium difficile) is the major pathogen associated with infectious diarrhea in humans. Concomitant with the increased incidence of C. difficile infection worldwide, there is an increasing concern regarding this infection type. This study reports a draft assembly and detailed sequence analysis of C. difficile strain ZJCDC-S82. The de novo assembled genome was 4.19 Mb in size, which includes 4,013 protein-coding genes, 41 rRNA genes, and 84 tRNA genes. Along with the nuclear genome, we also assembled sequencing information for a single plasmid consisting of 11,930 nucleotides. Comparative genomic analysis of C. difficile ZJCDC-S82 and two other previously published strains, such as M120 and CD630, showed extensive similarity. Phylogenetic analysis revealed that genetic diversity among C. difficile strains was not influenced by geographic location. Evolutionary analysis suggested that four genes encoding surface proteins exhibited positive selection in C. difficile ZJCDC-S82. Codon usage analysis indicated that C. difficile ZJCDC-S82 had high codon usage bias toward A/U-ended codons. Furthermore, codon usage patterns in C. difficile ZJCDC-S82 were predominantly affected by mutation pressure. Our results provide detailed information pertaining to the C. difficile genome associated with a strain from mainland China. This analysis will facilitate the understanding of genomic diversity and evolution of C. difficile strains in this region.

The prognostic value of plasma soluble CD40 ligand levels in patients with nasopharyngeal carcinoma.

BACKGROUND Serum soluble CD40 ligand (sCD40L) concentrations are increased in patients with nasopharyngeal carcinoma (NPC). This study further evaluated the relationship between plasma sCD40L concentrations and long-term survival of NPC. METHODS Plasma sCD40L concentrations of 312 patients and 312 healthy controls were determined using an ELISA. The associations of plasma sCD40L concentrations with 5-year overall survival, progression-free survival, distant metastasis-free survival, and locoregional relapse-free survival were investigated by univariate and multivariate analyses. RESULTS Plasma sCD40L concentrations were substantially higher in patients than in healthy subjects and also correlated highly with tumor classification, lymph node classification and tumor node metastasis stage. sCD40L emerged as an independent predictor for 5-year overall survival, progression-free survival, distant metastasis-free survival, and locoregional relapse-free survival using univariate and multivariate Cox regression analysis. CONCLUSIONS High plasma sCD40L concentration is correlated with stage progression of NPC as well as associated with poor survival of NPC. It is suggested that sCD40L should have the potential to be a prognostic biomarker for NPC.