Background
Accumulating evidence shows an overabundance of
Fusobacterium nucleatum
in colorectal tumor tissues. However, the correlation between the absolute copy number of
F. nucleatum
in colorectal ...cancer tissues and colorectal cancer progression is unclear from previous reports. Therefore, we performed a study to compare the abundance of
F. nucleatum
in colorectal tissues with clinicopathologic and molecular features of colorectal cancer.
Methods
We collected 100 colorectal cancer tissues and 72 matched normal-appearing mucosal tissues. Absolute copy numbers of
F. nucleatum
were measured by droplet digital PCR.
Results
The detection rates of
F. nucleatum
were 63.9% (46/72) in normal-appearing mucosal tissues and 75.0% (75/100) in CRC tissue samples. The median copy number of
F. nucleatum
was 0.4/ng DNA in the normal-appearing colorectal mucosa in patients with colorectal cancer and 1.9/ng DNA in the colorectal cancer tissues (
P
= 0.0031).
F. nucleatum
copy numbers in stage IV colorectal cancer tissues were significantly higher than those in the normal-appearing mucosa in patients with colorectal cancer (
P
= 0.0016). The abundance of
F. nucleatum
in colorectal cancer tissues correlated with tumor size and KRAS mutation and was significantly associated with shorter overall survival times; this trend was notable in the patients with stage IV colorectal cancer. Focusing on normal-appearing mucosa in the patients with colorectal cancer, the
F. nucleatum
copy number was significantly higher in the patients with stage IV rather than stages I–III.
Conclusion
These results suggest that determining
F. nucleatum
levels may help predict clinical outcomes in colorectal cancer patients. Further confirmatory studies using independent datasets are required to confirm our findings.
The Epstein-Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma (EBVaGC), all tumor cells harbor the clonal EBV genome. The ...expression of latent EBV genes is strictly regulated through the methylation of EBV DNA. The methylation of viral DNA regulates the type of EBV latency, and methylation of the tumor suppressor genes is a key abnormality in EBVaGC. The methylation frequencies of several tumor suppressor genes and cell adhesion molecules are significantly higher in EBVaGC than in control cases. EBV-derived microRNAs repress translation from viral and host mRNAs. EBV regulates the expression of non-coding RNA in gastric carcinoma. With regard to the clinical application of demethylating agents against EBVaGC, we investigated the effects of decitabine against the EBVaGC cell lines. Decitabine inhibited the cell growth of EBVaGC cells. The promoter regions of p73 and Runt-related transcription factor 3(RUNX3) were demethylated, and their expression was upregulated by the treatment. We review the role of epigenetic regulation in the development and maintenance of EBVaGC and discuss the therapeutic application of DNA demethylating agents for EBVaGC.
Although human occupancy is a source of airborne bacteria, the role of walkers on bacterial communities in built environments is poorly understood. Therefore, we visualized the impact of walker ...occupancy combined with other factors (temperature, humidity, atmospheric pressure, dust particles) on airborne bacterial features in the Sapporo underground pedestrian space in Sapporo, Japan. Air samples (n = 18; 4,800L/each sample) were collected at 8:00 h to 20:00 h on 3 days (regular sampling) and at early morning / late night (5:50 h to 7:50 h / 22:15 h to 24:45 h) on a day (baseline sampling), and the number of CFUs (colony forming units) OTUs (operational taxonomic units) and other factors were determined. The results revealed that temperature, humidity, and atmospheric pressure changed with weather. The number of walkers increased greatly in the morning and evening on each regular sampling day, although total walker numbers did not differ significantly among regular sampling days. A slight increase in small dust particles (0.3-0.5μm) was observed on the days with higher temperature regardless of regular or baseline sampling. At the period on regular sampling, CFU levels varied irregularly among days, and the OTUs of 22-phylum types were observed, with the majority being from Firmicutes or Proteobacteria (γ-), including Staphylococcus sp. derived from human individuals. The data obtained from regular samplings reveled that although no direct interaction of walker occupancy and airborne CFU and OTU features was observed upon Pearson's correlation analysis, cluster analysis indicated an obvious lineage consisting of walker occupancy, CFU numbers, OTU types, small dust particles, and seasonal factors (including temperature and humidity). Meanwhile, at the period on baseline sampling both walker and CFU numbers were similarly minimal. Taken together, the results revealed a positive correlation of walker occupancy with airborne bacteria that increased with increases in temperature and humidity in the presence of airborne small particles. Moreover, the results indicated that small dust particles at high temperature and humidity may be a crucial factor responsible for stabilizing the bacteria released from walkers in built environments. The findings presented herein advance our knowledge and understanding of the relationship between humans and bacterial communities in built environments, and will help improve public health in urban communities.
The Epstein-Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma, all tumor cells harbor the clonal EBV genome. Gastric ...carcinoma associated with EBV has distinct clinicopathological features, occurs predominately in men and in younger-aged individuals, and presents a generally diffuse histological type. Most cases of EBV-associated gastric carcinoma exhibit a histology rich in lymphocyte infiltration. The immunological reactiveness in the host may represent a relatively preferable prognosis in EBV-positive cases. This fact highlights the important role of EBV in the development of EBV-associated gastric carcinoma. We have clearly proved direct infection of human gastric epithelialcells by EBV. The infection was achieved by using a recombinant EBV. Promotion of growth by EBV infection was observed in the cells. Considerable data suggest that EBV may directly contribute to the development of EBV-associated GC. This tumor-promoting effect seems to involve multiple mechanisms, because EBV affects several host proteins and pathways that normally promote apoptosis and regulate cell proliferation.
We studied the comprehensive DNA methylation status in the naturally derived gastric adenocarcinoma cell line SNU‐719, which was infected with the Epstein–Barr virus (EBV) by methylated CpG island ...recovery on chip assay. To identify genes specifically methylated in EBV‐associated gastric carcinomas (EBVaGC), we focused on seven genes, TP73, BLU, FSD1, BCL7A, MARK1, SCRN1, and NKX3.1, based on the results of methylated CpG island recovery on chip assay. We confirmed DNA methylation of the genes by methylation‐specific PCR and bisulfite sequencing in SNU‐719. The expression of the genes, except for BCL7A, was upregulated by a combination of 5‐Aza‐2′‐deoxycytidine and trichostatin A treatment in SNU‐719. After the treatment, unmethylated DNA became detectable in all seven genes by methylation‐specific PCR. We verified DNA methylation of the genes in 75 primary gastric cancer tissues from 25 patients with EBVaGC and 50 EBV‐negative patients who were controls. The methylation frequencies of TP73, BLU, FSD1, BCL7A, MARK1, SCRN1, and NKX3.1 were significantly higher in EBVaGC than in EBV‐negative gastric carcinoma. We identified seven genes with promoter regions that were specifically methylated in EBVaGC. Inactivation of these genes may suppress their function as tumor suppressor genes or tumor‐associated antigens and help to develop and maintain EBVaGC.
We explored the bacteria present in the vaginal microbiota facilitating the prevalence of Chlamydia trachomatis in women visiting a community hospital in Sapporo, Japan, by amplicon sequencing. A ...total of 273 cervical swab samples were collected, and bacterial vaginosis was evaluated in all specimens by assessment of the Nugent score. In 16 of the samples, bacterial 16S rDNA could not be detected and they were therefore omitted from subsequent experiments (n = 257). A significant negative correlation was observed between the Nugent scores and the amount of Lactobacillus 16S rDNA. Among the 257 samples, chlamydial plasmid was detected in 20 samples and was used for amplicon sequencing. No significant association between the Nugent score and the prevalence of C. trachomatis was detected. Based on the results of chlamydial plasmid detection and the Nugent score, chlamydia-negative samples (n = 27) were randomly selected. Finally, the number of operational taxonomic units (OTUs) obtained from amplicon sequencing was compared between chlamydia-positive (n = 20) and -negative samples (n = 27), revealing that a significant difference was only detected for the OTU numbers of Enterobacteriaceae between the C. trachomatis-positive and -negative groups. However, almost all of the samples utilized for amplicon sequencing failed to grow on MacConkey agar plates and produce indole. Taken together, we concluded that traces of bacteria, not live bacteria, belonging to the Enterobacteriaceae indicated the flow of bacteria through the anogenital route along with gut indole, and the resulting impact on the prevalence of C. trachomatis in the cervicogenital tract of women in Japan.
Abstract Background The aim of this study was to assess surgical intervention strategies for congenital cystic lesions of the lungs (CCL), focusing on the safety of lung resection. Materials and ...methods The clinical features of 27 children (CCAM, n = 16; bronchial atresia, n = 4; bronchogenic cyst, n = 3; pulmonary sequestration, n = 3; lobar emphysema, n = 1) who were treated at our institution between 1995 and 2014 were analyzed. Results Of the 27 patients, 14 were asymptomatic, and 13 were symptomatic. The youngest symptomatic patient presented with pneumonia at 9 months of age. The mean age at surgery was 4 months in the asymptomatic group and 4.1 years in the symptomatic group. The mean operating time was 167 minutes in the asymptomatic group and 275 minutes in the symptomatic group (P < 0.001). The mean amount of intraoperative bleeding was 15 g in the asymptomatic group and 83.4 g in the symptomatic group (P < 0.05). All of the prenatally diagnosed patients underwent surgery within six months of birth. Three patients had remnant cystic lesions, all of which involved cystic lesions located over the lobulation anomalies of the lung. Conclusions To minimize surgical invasiveness, surgery for CCL should be performed during the asymptomatic period or within six months after birth.
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